media: uvcvideo: Do not alloc dev->status
Commit Message
UVC_MAX_STATUS_SIZE is 16, simplify the code by inlining dev->status.
Now that we are at it, remove all the castings.
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
To: Yunke Cao <yunkec@chromium.org>
To: Sergey Senozhatsky <senozhatsky@chromium.org>
To: Max Staudt <mstaudt@google.com>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: linux-media@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
drivers/media/usb/uvc/uvc_status.c | 69 ++++++++++++--------------------------
drivers/media/usb/uvc/uvcvideo.h | 22 +++++++++++-
2 files changed, 42 insertions(+), 49 deletions(-)
---
base-commit: 0ec5a38bf8499f403f81cb81a0e3a60887d1993c
change-id: 20221214-uvc-status-alloc-93becb783898
Best regards,
Comments
Hi
This is the next version of the previous patch including Sergey's comments.
It is on its own series now.
Regards!
On Wed, 14 Dec 2022 at 12:24, Ricardo Ribalda <ribalda@chromium.org> wrote:
>
> UVC_MAX_STATUS_SIZE is 16, simplify the code by inlining dev->status.
>
> Now that we are at it, remove all the castings.
>
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> ---
> To: Yunke Cao <yunkec@chromium.org>
> To: Sergey Senozhatsky <senozhatsky@chromium.org>
> To: Max Staudt <mstaudt@google.com>
> To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> To: Mauro Carvalho Chehab <mchehab@kernel.org>
> Cc: linux-media@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> ---
> drivers/media/usb/uvc/uvc_status.c | 69 ++++++++++++--------------------------
> drivers/media/usb/uvc/uvcvideo.h | 22 +++++++++++-
> 2 files changed, 42 insertions(+), 49 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_status.c b/drivers/media/usb/uvc/uvc_status.c
> index 7518ffce22ed..adf63e7616c9 100644
> --- a/drivers/media/usb/uvc/uvc_status.c
> +++ b/drivers/media/usb/uvc/uvc_status.c
> @@ -73,38 +73,24 @@ static void uvc_input_report_key(struct uvc_device *dev, unsigned int code,
> /* --------------------------------------------------------------------------
> * Status interrupt endpoint
> */
> -struct uvc_streaming_status {
> - u8 bStatusType;
> - u8 bOriginator;
> - u8 bEvent;
> - u8 bValue[];
> -} __packed;
> -
> -struct uvc_control_status {
> - u8 bStatusType;
> - u8 bOriginator;
> - u8 bEvent;
> - u8 bSelector;
> - u8 bAttribute;
> - u8 bValue[];
> -} __packed;
> -
> static void uvc_event_streaming(struct uvc_device *dev,
> - struct uvc_streaming_status *status, int len)
> + struct uvc_status *status, int len)
> {
> - if (len < 3) {
> + if (len <= offsetof(struct uvc_status, bEvent)) {
> uvc_dbg(dev, STATUS,
> "Invalid streaming status event received\n");
> return;
> }
>
> if (status->bEvent == 0) {
> - if (len < 4)
> + if (len <= offsetof(struct uvc_status, streaming))
> return;
> +
> uvc_dbg(dev, STATUS, "Button (intf %u) %s len %d\n",
> status->bOriginator,
> - status->bValue[0] ? "pressed" : "released", len);
> - uvc_input_report_key(dev, KEY_CAMERA, status->bValue[0]);
> + status->streaming.button ? "pressed" : "released", len);
> + uvc_input_report_key(dev, KEY_CAMERA,
> + status->streaming.button);
> } else {
> uvc_dbg(dev, STATUS, "Stream %u error event %02x len %d\n",
> status->bOriginator, status->bEvent, len);
> @@ -131,7 +117,7 @@ static struct uvc_control *uvc_event_entity_find_ctrl(struct uvc_entity *entity,
> }
>
> static struct uvc_control *uvc_event_find_ctrl(struct uvc_device *dev,
> - const struct uvc_control_status *status,
> + const struct uvc_status *status,
> struct uvc_video_chain **chain)
> {
> list_for_each_entry((*chain), &dev->chains, list) {
> @@ -143,7 +129,7 @@ static struct uvc_control *uvc_event_find_ctrl(struct uvc_device *dev,
> continue;
>
> ctrl = uvc_event_entity_find_ctrl(entity,
> - status->bSelector);
> + status->control.bSelector);
> if (ctrl)
> return ctrl;
> }
> @@ -153,7 +139,7 @@ static struct uvc_control *uvc_event_find_ctrl(struct uvc_device *dev,
> }
>
> static bool uvc_event_control(struct urb *urb,
> - const struct uvc_control_status *status, int len)
> + const struct uvc_status *status, int len)
> {
> static const char *attrs[] = { "value", "info", "failure", "min", "max" };
> struct uvc_device *dev = urb->context;
> @@ -161,24 +147,24 @@ static bool uvc_event_control(struct urb *urb,
> struct uvc_control *ctrl;
>
> if (len < 6 || status->bEvent != 0 ||
> - status->bAttribute >= ARRAY_SIZE(attrs)) {
> + status->control.bAttribute >= ARRAY_SIZE(attrs)) {
> uvc_dbg(dev, STATUS, "Invalid control status event received\n");
> return false;
> }
>
> uvc_dbg(dev, STATUS, "Control %u/%u %s change len %d\n",
> - status->bOriginator, status->bSelector,
> - attrs[status->bAttribute], len);
> + status->bOriginator, status->control.bSelector,
> + attrs[status->control.bAttribute], len);
>
> /* Find the control. */
> ctrl = uvc_event_find_ctrl(dev, status, &chain);
> if (!ctrl)
> return false;
>
> - switch (status->bAttribute) {
> + switch (status->control.bAttribute) {
> case UVC_CTRL_VALUE_CHANGE:
> return uvc_ctrl_status_event_async(urb, chain, ctrl,
> - status->bValue);
> + status->control.bValue);
>
> case UVC_CTRL_INFO_CHANGE:
> case UVC_CTRL_FAILURE_CHANGE:
> @@ -214,28 +200,22 @@ static void uvc_status_complete(struct urb *urb)
>
> len = urb->actual_length;
> if (len > 0) {
> - switch (dev->status[0] & 0x0f) {
> + switch (dev->status.bStatusType & 0x0f) {
> case UVC_STATUS_TYPE_CONTROL: {
> - struct uvc_control_status *status =
> - (struct uvc_control_status *)dev->status;
> -
> - if (uvc_event_control(urb, status, len))
> + if (uvc_event_control(urb, &dev->status, len))
> /* The URB will be resubmitted in work context. */
> return;
> break;
> }
>
> case UVC_STATUS_TYPE_STREAMING: {
> - struct uvc_streaming_status *status =
> - (struct uvc_streaming_status *)dev->status;
> -
> - uvc_event_streaming(dev, status, len);
> + uvc_event_streaming(dev, &dev->status, len);
> break;
> }
>
> default:
> uvc_dbg(dev, STATUS, "Unknown status event type %u\n",
> - dev->status[0]);
> + dev->status.bStatusType);
> break;
> }
> }
> @@ -259,15 +239,9 @@ int uvc_status_init(struct uvc_device *dev)
>
> uvc_input_init(dev);
>
> - dev->status = kzalloc(UVC_MAX_STATUS_SIZE, GFP_KERNEL);
> - if (dev->status == NULL)
> - return -ENOMEM;
> -
> dev->int_urb = usb_alloc_urb(0, GFP_KERNEL);
> - if (dev->int_urb == NULL) {
> - kfree(dev->status);
> + if (!dev->int_urb)
> return -ENOMEM;
> - }
>
> pipe = usb_rcvintpipe(dev->udev, ep->desc.bEndpointAddress);
>
> @@ -281,7 +255,7 @@ int uvc_status_init(struct uvc_device *dev)
> interval = fls(interval) - 1;
>
> usb_fill_int_urb(dev->int_urb, dev->udev, pipe,
> - dev->status, UVC_MAX_STATUS_SIZE, uvc_status_complete,
> + &dev->status, sizeof(dev->status), uvc_status_complete,
> dev, interval);
>
> return 0;
> @@ -296,7 +270,6 @@ void uvc_status_unregister(struct uvc_device *dev)
> void uvc_status_cleanup(struct uvc_device *dev)
> {
> usb_free_urb(dev->int_urb);
> - kfree(dev->status);
> }
>
> int uvc_status_start(struct uvc_device *dev, gfp_t flags)
> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> index df93db259312..cdd2e328acc2 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -527,6 +527,26 @@ struct uvc_device_info {
> const struct uvc_control_mapping **mappings;
> };
>
> +struct uvc_status_streaming {
> + u8 button;
> +} __packed;
> +
> +struct uvc_status_control {
> + u8 bSelector;
> + u8 bAttribute;
> + u8 bValue[11];
> +} __packed;
> +
> +struct uvc_status {
> + u8 bStatusType;
> + u8 bOriginator;
> + u8 bEvent;
> + union {
> + struct uvc_status_control control;
> + struct uvc_status_streaming streaming;
> + };
> +} __packed;
> +
> struct uvc_device {
> struct usb_device *udev;
> struct usb_interface *intf;
> @@ -559,7 +579,7 @@ struct uvc_device {
> /* Status Interrupt Endpoint */
> struct usb_host_endpoint *int_ep;
> struct urb *int_urb;
> - u8 *status;
> + struct uvc_status status;
> struct input_dev *input;
> char input_phys[64];
>
>
> ---
> base-commit: 0ec5a38bf8499f403f81cb81a0e3a60887d1993c
> change-id: 20221214-uvc-status-alloc-93becb783898
>
> Best regards,
> --
> Ricardo Ribalda <ribalda@chromium.org>
Hi Ricardo,
Thank you for the patch.
On Wed, Dec 14, 2022 at 12:23:41PM +0100, Ricardo Ribalda wrote:
> UVC_MAX_STATUS_SIZE is 16, simplify the code by inlining dev->status.
The reason why uvc_status is allocated dynamically is to ensure cache
line alignment, as the USB host controller may DMA to the buffer.
> Now that we are at it, remove all the castings.
>
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> ---
> To: Yunke Cao <yunkec@chromium.org>
> To: Sergey Senozhatsky <senozhatsky@chromium.org>
> To: Max Staudt <mstaudt@google.com>
> To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> To: Mauro Carvalho Chehab <mchehab@kernel.org>
> Cc: linux-media@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> ---
> drivers/media/usb/uvc/uvc_status.c | 69 ++++++++++++--------------------------
> drivers/media/usb/uvc/uvcvideo.h | 22 +++++++++++-
> 2 files changed, 42 insertions(+), 49 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_status.c b/drivers/media/usb/uvc/uvc_status.c
> index 7518ffce22ed..adf63e7616c9 100644
> --- a/drivers/media/usb/uvc/uvc_status.c
> +++ b/drivers/media/usb/uvc/uvc_status.c
> @@ -73,38 +73,24 @@ static void uvc_input_report_key(struct uvc_device *dev, unsigned int code,
> /* --------------------------------------------------------------------------
> * Status interrupt endpoint
> */
> -struct uvc_streaming_status {
> - u8 bStatusType;
> - u8 bOriginator;
> - u8 bEvent;
> - u8 bValue[];
> -} __packed;
> -
> -struct uvc_control_status {
> - u8 bStatusType;
> - u8 bOriginator;
> - u8 bEvent;
> - u8 bSelector;
> - u8 bAttribute;
> - u8 bValue[];
> -} __packed;
> -
> static void uvc_event_streaming(struct uvc_device *dev,
> - struct uvc_streaming_status *status, int len)
> + struct uvc_status *status, int len)
> {
> - if (len < 3) {
> + if (len <= offsetof(struct uvc_status, bEvent)) {
> uvc_dbg(dev, STATUS,
> "Invalid streaming status event received\n");
> return;
> }
>
> if (status->bEvent == 0) {
> - if (len < 4)
> + if (len <= offsetof(struct uvc_status, streaming))
> return;
> +
> uvc_dbg(dev, STATUS, "Button (intf %u) %s len %d\n",
> status->bOriginator,
> - status->bValue[0] ? "pressed" : "released", len);
> - uvc_input_report_key(dev, KEY_CAMERA, status->bValue[0]);
> + status->streaming.button ? "pressed" : "released", len);
> + uvc_input_report_key(dev, KEY_CAMERA,
> + status->streaming.button);
> } else {
> uvc_dbg(dev, STATUS, "Stream %u error event %02x len %d\n",
> status->bOriginator, status->bEvent, len);
> @@ -131,7 +117,7 @@ static struct uvc_control *uvc_event_entity_find_ctrl(struct uvc_entity *entity,
> }
>
> static struct uvc_control *uvc_event_find_ctrl(struct uvc_device *dev,
> - const struct uvc_control_status *status,
> + const struct uvc_status *status,
> struct uvc_video_chain **chain)
> {
> list_for_each_entry((*chain), &dev->chains, list) {
> @@ -143,7 +129,7 @@ static struct uvc_control *uvc_event_find_ctrl(struct uvc_device *dev,
> continue;
>
> ctrl = uvc_event_entity_find_ctrl(entity,
> - status->bSelector);
> + status->control.bSelector);
> if (ctrl)
> return ctrl;
> }
> @@ -153,7 +139,7 @@ static struct uvc_control *uvc_event_find_ctrl(struct uvc_device *dev,
> }
>
> static bool uvc_event_control(struct urb *urb,
> - const struct uvc_control_status *status, int len)
> + const struct uvc_status *status, int len)
> {
> static const char *attrs[] = { "value", "info", "failure", "min", "max" };
> struct uvc_device *dev = urb->context;
> @@ -161,24 +147,24 @@ static bool uvc_event_control(struct urb *urb,
> struct uvc_control *ctrl;
>
> if (len < 6 || status->bEvent != 0 ||
> - status->bAttribute >= ARRAY_SIZE(attrs)) {
> + status->control.bAttribute >= ARRAY_SIZE(attrs)) {
> uvc_dbg(dev, STATUS, "Invalid control status event received\n");
> return false;
> }
>
> uvc_dbg(dev, STATUS, "Control %u/%u %s change len %d\n",
> - status->bOriginator, status->bSelector,
> - attrs[status->bAttribute], len);
> + status->bOriginator, status->control.bSelector,
> + attrs[status->control.bAttribute], len);
>
> /* Find the control. */
> ctrl = uvc_event_find_ctrl(dev, status, &chain);
> if (!ctrl)
> return false;
>
> - switch (status->bAttribute) {
> + switch (status->control.bAttribute) {
> case UVC_CTRL_VALUE_CHANGE:
> return uvc_ctrl_status_event_async(urb, chain, ctrl,
> - status->bValue);
> + status->control.bValue);
>
> case UVC_CTRL_INFO_CHANGE:
> case UVC_CTRL_FAILURE_CHANGE:
> @@ -214,28 +200,22 @@ static void uvc_status_complete(struct urb *urb)
>
> len = urb->actual_length;
> if (len > 0) {
> - switch (dev->status[0] & 0x0f) {
> + switch (dev->status.bStatusType & 0x0f) {
> case UVC_STATUS_TYPE_CONTROL: {
> - struct uvc_control_status *status =
> - (struct uvc_control_status *)dev->status;
> -
> - if (uvc_event_control(urb, status, len))
> + if (uvc_event_control(urb, &dev->status, len))
> /* The URB will be resubmitted in work context. */
> return;
> break;
> }
>
> case UVC_STATUS_TYPE_STREAMING: {
> - struct uvc_streaming_status *status =
> - (struct uvc_streaming_status *)dev->status;
> -
> - uvc_event_streaming(dev, status, len);
> + uvc_event_streaming(dev, &dev->status, len);
> break;
> }
>
> default:
> uvc_dbg(dev, STATUS, "Unknown status event type %u\n",
> - dev->status[0]);
> + dev->status.bStatusType);
> break;
> }
> }
> @@ -259,15 +239,9 @@ int uvc_status_init(struct uvc_device *dev)
>
> uvc_input_init(dev);
>
> - dev->status = kzalloc(UVC_MAX_STATUS_SIZE, GFP_KERNEL);
> - if (dev->status == NULL)
> - return -ENOMEM;
> -
> dev->int_urb = usb_alloc_urb(0, GFP_KERNEL);
> - if (dev->int_urb == NULL) {
> - kfree(dev->status);
> + if (!dev->int_urb)
> return -ENOMEM;
> - }
>
> pipe = usb_rcvintpipe(dev->udev, ep->desc.bEndpointAddress);
>
> @@ -281,7 +255,7 @@ int uvc_status_init(struct uvc_device *dev)
> interval = fls(interval) - 1;
>
> usb_fill_int_urb(dev->int_urb, dev->udev, pipe,
> - dev->status, UVC_MAX_STATUS_SIZE, uvc_status_complete,
> + &dev->status, sizeof(dev->status), uvc_status_complete,
> dev, interval);
>
> return 0;
> @@ -296,7 +270,6 @@ void uvc_status_unregister(struct uvc_device *dev)
> void uvc_status_cleanup(struct uvc_device *dev)
> {
> usb_free_urb(dev->int_urb);
> - kfree(dev->status);
> }
>
> int uvc_status_start(struct uvc_device *dev, gfp_t flags)
> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> index df93db259312..cdd2e328acc2 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -527,6 +527,26 @@ struct uvc_device_info {
> const struct uvc_control_mapping **mappings;
> };
>
> +struct uvc_status_streaming {
> + u8 button;
> +} __packed;
> +
> +struct uvc_status_control {
> + u8 bSelector;
> + u8 bAttribute;
> + u8 bValue[11];
> +} __packed;
> +
> +struct uvc_status {
> + u8 bStatusType;
> + u8 bOriginator;
> + u8 bEvent;
> + union {
> + struct uvc_status_control control;
> + struct uvc_status_streaming streaming;
> + };
> +} __packed;
> +
> struct uvc_device {
> struct usb_device *udev;
> struct usb_interface *intf;
> @@ -559,7 +579,7 @@ struct uvc_device {
> /* Status Interrupt Endpoint */
> struct usb_host_endpoint *int_ep;
> struct urb *int_urb;
> - u8 *status;
> + struct uvc_status status;
> struct input_dev *input;
> char input_phys[64];
>
>
> ---
> base-commit: 0ec5a38bf8499f403f81cb81a0e3a60887d1993c
> change-id: 20221214-uvc-status-alloc-93becb783898
On Wed, Dec 14, 2022 at 02:45:31PM +0200, Laurent Pinchart wrote:
> Hi Ricardo,
>
> Thank you for the patch.
>
> On Wed, Dec 14, 2022 at 12:23:41PM +0100, Ricardo Ribalda wrote:
> > UVC_MAX_STATUS_SIZE is 16, simplify the code by inlining dev->status.
>
> The reason why uvc_status is allocated dynamically is to ensure cache
> line alignment, as the USB host controller may DMA to the buffer.
See
commit a31a4055473bf0a7b2b06cb2262347200d0711e1
Author: Ming Lei <tom.leiming@gmail.com>
Date: Tue Sep 16 03:32:20 2008 -0300
V4L/DVB:usbvideo:don't use part of buffer for USB transfer #4
The status[] is part of uvc_device structure. We can't make sure
the address of status is at a cache-line boundary in all archs,so
status[] might share a cache-line with some fields in uvc_structure.
This can lead to some cache coherence issues(http://lwn.net/Articles/2265/).
Use dynamically allocated buffer instead.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
> > Now that we are at it, remove all the castings.
> >
> > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> > ---
> > To: Yunke Cao <yunkec@chromium.org>
> > To: Sergey Senozhatsky <senozhatsky@chromium.org>
> > To: Max Staudt <mstaudt@google.com>
> > To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > To: Mauro Carvalho Chehab <mchehab@kernel.org>
> > Cc: linux-media@vger.kernel.org
> > Cc: linux-kernel@vger.kernel.org
> > ---
> > drivers/media/usb/uvc/uvc_status.c | 69 ++++++++++++--------------------------
> > drivers/media/usb/uvc/uvcvideo.h | 22 +++++++++++-
> > 2 files changed, 42 insertions(+), 49 deletions(-)
> >
> > diff --git a/drivers/media/usb/uvc/uvc_status.c b/drivers/media/usb/uvc/uvc_status.c
> > index 7518ffce22ed..adf63e7616c9 100644
> > --- a/drivers/media/usb/uvc/uvc_status.c
> > +++ b/drivers/media/usb/uvc/uvc_status.c
> > @@ -73,38 +73,24 @@ static void uvc_input_report_key(struct uvc_device *dev, unsigned int code,
> > /* --------------------------------------------------------------------------
> > * Status interrupt endpoint
> > */
> > -struct uvc_streaming_status {
> > - u8 bStatusType;
> > - u8 bOriginator;
> > - u8 bEvent;
> > - u8 bValue[];
> > -} __packed;
> > -
> > -struct uvc_control_status {
> > - u8 bStatusType;
> > - u8 bOriginator;
> > - u8 bEvent;
> > - u8 bSelector;
> > - u8 bAttribute;
> > - u8 bValue[];
> > -} __packed;
> > -
> > static void uvc_event_streaming(struct uvc_device *dev,
> > - struct uvc_streaming_status *status, int len)
> > + struct uvc_status *status, int len)
> > {
> > - if (len < 3) {
> > + if (len <= offsetof(struct uvc_status, bEvent)) {
> > uvc_dbg(dev, STATUS,
> > "Invalid streaming status event received\n");
> > return;
> > }
> >
> > if (status->bEvent == 0) {
> > - if (len < 4)
> > + if (len <= offsetof(struct uvc_status, streaming))
> > return;
> > +
> > uvc_dbg(dev, STATUS, "Button (intf %u) %s len %d\n",
> > status->bOriginator,
> > - status->bValue[0] ? "pressed" : "released", len);
> > - uvc_input_report_key(dev, KEY_CAMERA, status->bValue[0]);
> > + status->streaming.button ? "pressed" : "released", len);
> > + uvc_input_report_key(dev, KEY_CAMERA,
> > + status->streaming.button);
> > } else {
> > uvc_dbg(dev, STATUS, "Stream %u error event %02x len %d\n",
> > status->bOriginator, status->bEvent, len);
> > @@ -131,7 +117,7 @@ static struct uvc_control *uvc_event_entity_find_ctrl(struct uvc_entity *entity,
> > }
> >
> > static struct uvc_control *uvc_event_find_ctrl(struct uvc_device *dev,
> > - const struct uvc_control_status *status,
> > + const struct uvc_status *status,
> > struct uvc_video_chain **chain)
> > {
> > list_for_each_entry((*chain), &dev->chains, list) {
> > @@ -143,7 +129,7 @@ static struct uvc_control *uvc_event_find_ctrl(struct uvc_device *dev,
> > continue;
> >
> > ctrl = uvc_event_entity_find_ctrl(entity,
> > - status->bSelector);
> > + status->control.bSelector);
> > if (ctrl)
> > return ctrl;
> > }
> > @@ -153,7 +139,7 @@ static struct uvc_control *uvc_event_find_ctrl(struct uvc_device *dev,
> > }
> >
> > static bool uvc_event_control(struct urb *urb,
> > - const struct uvc_control_status *status, int len)
> > + const struct uvc_status *status, int len)
> > {
> > static const char *attrs[] = { "value", "info", "failure", "min", "max" };
> > struct uvc_device *dev = urb->context;
> > @@ -161,24 +147,24 @@ static bool uvc_event_control(struct urb *urb,
> > struct uvc_control *ctrl;
> >
> > if (len < 6 || status->bEvent != 0 ||
> > - status->bAttribute >= ARRAY_SIZE(attrs)) {
> > + status->control.bAttribute >= ARRAY_SIZE(attrs)) {
> > uvc_dbg(dev, STATUS, "Invalid control status event received\n");
> > return false;
> > }
> >
> > uvc_dbg(dev, STATUS, "Control %u/%u %s change len %d\n",
> > - status->bOriginator, status->bSelector,
> > - attrs[status->bAttribute], len);
> > + status->bOriginator, status->control.bSelector,
> > + attrs[status->control.bAttribute], len);
> >
> > /* Find the control. */
> > ctrl = uvc_event_find_ctrl(dev, status, &chain);
> > if (!ctrl)
> > return false;
> >
> > - switch (status->bAttribute) {
> > + switch (status->control.bAttribute) {
> > case UVC_CTRL_VALUE_CHANGE:
> > return uvc_ctrl_status_event_async(urb, chain, ctrl,
> > - status->bValue);
> > + status->control.bValue);
> >
> > case UVC_CTRL_INFO_CHANGE:
> > case UVC_CTRL_FAILURE_CHANGE:
> > @@ -214,28 +200,22 @@ static void uvc_status_complete(struct urb *urb)
> >
> > len = urb->actual_length;
> > if (len > 0) {
> > - switch (dev->status[0] & 0x0f) {
> > + switch (dev->status.bStatusType & 0x0f) {
> > case UVC_STATUS_TYPE_CONTROL: {
> > - struct uvc_control_status *status =
> > - (struct uvc_control_status *)dev->status;
> > -
> > - if (uvc_event_control(urb, status, len))
> > + if (uvc_event_control(urb, &dev->status, len))
> > /* The URB will be resubmitted in work context. */
> > return;
> > break;
> > }
> >
> > case UVC_STATUS_TYPE_STREAMING: {
> > - struct uvc_streaming_status *status =
> > - (struct uvc_streaming_status *)dev->status;
> > -
> > - uvc_event_streaming(dev, status, len);
> > + uvc_event_streaming(dev, &dev->status, len);
> > break;
> > }
> >
> > default:
> > uvc_dbg(dev, STATUS, "Unknown status event type %u\n",
> > - dev->status[0]);
> > + dev->status.bStatusType);
> > break;
> > }
> > }
> > @@ -259,15 +239,9 @@ int uvc_status_init(struct uvc_device *dev)
> >
> > uvc_input_init(dev);
> >
> > - dev->status = kzalloc(UVC_MAX_STATUS_SIZE, GFP_KERNEL);
> > - if (dev->status == NULL)
> > - return -ENOMEM;
> > -
> > dev->int_urb = usb_alloc_urb(0, GFP_KERNEL);
> > - if (dev->int_urb == NULL) {
> > - kfree(dev->status);
> > + if (!dev->int_urb)
> > return -ENOMEM;
> > - }
> >
> > pipe = usb_rcvintpipe(dev->udev, ep->desc.bEndpointAddress);
> >
> > @@ -281,7 +255,7 @@ int uvc_status_init(struct uvc_device *dev)
> > interval = fls(interval) - 1;
> >
> > usb_fill_int_urb(dev->int_urb, dev->udev, pipe,
> > - dev->status, UVC_MAX_STATUS_SIZE, uvc_status_complete,
> > + &dev->status, sizeof(dev->status), uvc_status_complete,
> > dev, interval);
> >
> > return 0;
> > @@ -296,7 +270,6 @@ void uvc_status_unregister(struct uvc_device *dev)
> > void uvc_status_cleanup(struct uvc_device *dev)
> > {
> > usb_free_urb(dev->int_urb);
> > - kfree(dev->status);
> > }
> >
> > int uvc_status_start(struct uvc_device *dev, gfp_t flags)
> > diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> > index df93db259312..cdd2e328acc2 100644
> > --- a/drivers/media/usb/uvc/uvcvideo.h
> > +++ b/drivers/media/usb/uvc/uvcvideo.h
> > @@ -527,6 +527,26 @@ struct uvc_device_info {
> > const struct uvc_control_mapping **mappings;
> > };
> >
> > +struct uvc_status_streaming {
> > + u8 button;
> > +} __packed;
> > +
> > +struct uvc_status_control {
> > + u8 bSelector;
> > + u8 bAttribute;
> > + u8 bValue[11];
> > +} __packed;
> > +
> > +struct uvc_status {
> > + u8 bStatusType;
> > + u8 bOriginator;
> > + u8 bEvent;
> > + union {
> > + struct uvc_status_control control;
> > + struct uvc_status_streaming streaming;
> > + };
> > +} __packed;
> > +
> > struct uvc_device {
> > struct usb_device *udev;
> > struct usb_interface *intf;
> > @@ -559,7 +579,7 @@ struct uvc_device {
> > /* Status Interrupt Endpoint */
> > struct usb_host_endpoint *int_ep;
> > struct urb *int_urb;
> > - u8 *status;
> > + struct uvc_status status;
> > struct input_dev *input;
> > char input_phys[64];
> >
> >
> > ---
> > base-commit: 0ec5a38bf8499f403f81cb81a0e3a60887d1993c
> > change-id: 20221214-uvc-status-alloc-93becb783898
On (22/12/14 14:45), Laurent Pinchart wrote:
> On Wed, Dec 14, 2022 at 12:23:41PM +0100, Ricardo Ribalda wrote:
> > UVC_MAX_STATUS_SIZE is 16, simplify the code by inlining dev->status.
>
> The reason why uvc_status is allocated dynamically is to ensure cache
> line alignment, as the USB host controller may DMA to the buffer.
Oh, that's a very subtle detail.
> > +struct uvc_status_streaming {
> > + u8 button;
> > +} __packed;
> > +
> > +struct uvc_status_control {
> > + u8 bSelector;
> > + u8 bAttribute;
> > + u8 bValue[11];
> > +} __packed;
> > +
> > +struct uvc_status {
> > + u8 bStatusType;
> > + u8 bOriginator;
> > + u8 bEvent;
> > + union {
> > + struct uvc_status_control control;
> > + struct uvc_status_streaming streaming;
> > + };
> > +} __packed;
> > +
> > struct uvc_device {
> > struct usb_device *udev;
> > struct usb_interface *intf;
> > @@ -559,7 +579,7 @@ struct uvc_device {
> > /* Status Interrupt Endpoint */
> > struct usb_host_endpoint *int_ep;
> > struct urb *int_urb;
> > - u8 *status;
> > + struct uvc_status status;
So we can do something like this maybe?
+ struct uvc_status status ____cacheline_aligned;
And this actually even improves code readability, IMHO, in a
sense that we explicitly say that it has to be cache aligned.
@@ -73,38 +73,24 @@ static void uvc_input_report_key(struct uvc_device *dev, unsigned int code,
/* --------------------------------------------------------------------------
* Status interrupt endpoint
*/
-struct uvc_streaming_status {
- u8 bStatusType;
- u8 bOriginator;
- u8 bEvent;
- u8 bValue[];
-} __packed;
-
-struct uvc_control_status {
- u8 bStatusType;
- u8 bOriginator;
- u8 bEvent;
- u8 bSelector;
- u8 bAttribute;
- u8 bValue[];
-} __packed;
-
static void uvc_event_streaming(struct uvc_device *dev,
- struct uvc_streaming_status *status, int len)
+ struct uvc_status *status, int len)
{
- if (len < 3) {
+ if (len <= offsetof(struct uvc_status, bEvent)) {
uvc_dbg(dev, STATUS,
"Invalid streaming status event received\n");
return;
}
if (status->bEvent == 0) {
- if (len < 4)
+ if (len <= offsetof(struct uvc_status, streaming))
return;
+
uvc_dbg(dev, STATUS, "Button (intf %u) %s len %d\n",
status->bOriginator,
- status->bValue[0] ? "pressed" : "released", len);
- uvc_input_report_key(dev, KEY_CAMERA, status->bValue[0]);
+ status->streaming.button ? "pressed" : "released", len);
+ uvc_input_report_key(dev, KEY_CAMERA,
+ status->streaming.button);
} else {
uvc_dbg(dev, STATUS, "Stream %u error event %02x len %d\n",
status->bOriginator, status->bEvent, len);
@@ -131,7 +117,7 @@ static struct uvc_control *uvc_event_entity_find_ctrl(struct uvc_entity *entity,
}
static struct uvc_control *uvc_event_find_ctrl(struct uvc_device *dev,
- const struct uvc_control_status *status,
+ const struct uvc_status *status,
struct uvc_video_chain **chain)
{
list_for_each_entry((*chain), &dev->chains, list) {
@@ -143,7 +129,7 @@ static struct uvc_control *uvc_event_find_ctrl(struct uvc_device *dev,
continue;
ctrl = uvc_event_entity_find_ctrl(entity,
- status->bSelector);
+ status->control.bSelector);
if (ctrl)
return ctrl;
}
@@ -153,7 +139,7 @@ static struct uvc_control *uvc_event_find_ctrl(struct uvc_device *dev,
}
static bool uvc_event_control(struct urb *urb,
- const struct uvc_control_status *status, int len)
+ const struct uvc_status *status, int len)
{
static const char *attrs[] = { "value", "info", "failure", "min", "max" };
struct uvc_device *dev = urb->context;
@@ -161,24 +147,24 @@ static bool uvc_event_control(struct urb *urb,
struct uvc_control *ctrl;
if (len < 6 || status->bEvent != 0 ||
- status->bAttribute >= ARRAY_SIZE(attrs)) {
+ status->control.bAttribute >= ARRAY_SIZE(attrs)) {
uvc_dbg(dev, STATUS, "Invalid control status event received\n");
return false;
}
uvc_dbg(dev, STATUS, "Control %u/%u %s change len %d\n",
- status->bOriginator, status->bSelector,
- attrs[status->bAttribute], len);
+ status->bOriginator, status->control.bSelector,
+ attrs[status->control.bAttribute], len);
/* Find the control. */
ctrl = uvc_event_find_ctrl(dev, status, &chain);
if (!ctrl)
return false;
- switch (status->bAttribute) {
+ switch (status->control.bAttribute) {
case UVC_CTRL_VALUE_CHANGE:
return uvc_ctrl_status_event_async(urb, chain, ctrl,
- status->bValue);
+ status->control.bValue);
case UVC_CTRL_INFO_CHANGE:
case UVC_CTRL_FAILURE_CHANGE:
@@ -214,28 +200,22 @@ static void uvc_status_complete(struct urb *urb)
len = urb->actual_length;
if (len > 0) {
- switch (dev->status[0] & 0x0f) {
+ switch (dev->status.bStatusType & 0x0f) {
case UVC_STATUS_TYPE_CONTROL: {
- struct uvc_control_status *status =
- (struct uvc_control_status *)dev->status;
-
- if (uvc_event_control(urb, status, len))
+ if (uvc_event_control(urb, &dev->status, len))
/* The URB will be resubmitted in work context. */
return;
break;
}
case UVC_STATUS_TYPE_STREAMING: {
- struct uvc_streaming_status *status =
- (struct uvc_streaming_status *)dev->status;
-
- uvc_event_streaming(dev, status, len);
+ uvc_event_streaming(dev, &dev->status, len);
break;
}
default:
uvc_dbg(dev, STATUS, "Unknown status event type %u\n",
- dev->status[0]);
+ dev->status.bStatusType);
break;
}
}
@@ -259,15 +239,9 @@ int uvc_status_init(struct uvc_device *dev)
uvc_input_init(dev);
- dev->status = kzalloc(UVC_MAX_STATUS_SIZE, GFP_KERNEL);
- if (dev->status == NULL)
- return -ENOMEM;
-
dev->int_urb = usb_alloc_urb(0, GFP_KERNEL);
- if (dev->int_urb == NULL) {
- kfree(dev->status);
+ if (!dev->int_urb)
return -ENOMEM;
- }
pipe = usb_rcvintpipe(dev->udev, ep->desc.bEndpointAddress);
@@ -281,7 +255,7 @@ int uvc_status_init(struct uvc_device *dev)
interval = fls(interval) - 1;
usb_fill_int_urb(dev->int_urb, dev->udev, pipe,
- dev->status, UVC_MAX_STATUS_SIZE, uvc_status_complete,
+ &dev->status, sizeof(dev->status), uvc_status_complete,
dev, interval);
return 0;
@@ -296,7 +270,6 @@ void uvc_status_unregister(struct uvc_device *dev)
void uvc_status_cleanup(struct uvc_device *dev)
{
usb_free_urb(dev->int_urb);
- kfree(dev->status);
}
int uvc_status_start(struct uvc_device *dev, gfp_t flags)
@@ -527,6 +527,26 @@ struct uvc_device_info {
const struct uvc_control_mapping **mappings;
};
+struct uvc_status_streaming {
+ u8 button;
+} __packed;
+
+struct uvc_status_control {
+ u8 bSelector;
+ u8 bAttribute;
+ u8 bValue[11];
+} __packed;
+
+struct uvc_status {
+ u8 bStatusType;
+ u8 bOriginator;
+ u8 bEvent;
+ union {
+ struct uvc_status_control control;
+ struct uvc_status_streaming streaming;
+ };
+} __packed;
+
struct uvc_device {
struct usb_device *udev;
struct usb_interface *intf;
@@ -559,7 +579,7 @@ struct uvc_device {
/* Status Interrupt Endpoint */
struct usb_host_endpoint *int_ep;
struct urb *int_urb;
- u8 *status;
+ struct uvc_status status;
struct input_dev *input;
char input_phys[64];