diff mbox series

[v2,2/6] can: esd_usb: Replace initializer macros used for struct can_bittiming_const

Message ID 20230519195600.420644-3-frank.jungclaus@esd.eu
State New
Headers
Series can: esd_usb: More preparation before supporting esd CAN-USB/3 |

Commit Message

Frank Jungclaus May 19, 2023, 7:55 p.m. UTC 
  Replace the macros used to initialize the members of struct
can_bittiming_const with direct values. Then also use those struct
members to do the calculations in esd_usb2_set_bittiming().

Link: https://lore.kernel.org/all/CAMZ6RqLaDNy-fZ2G0+QMhUEckkXLL+ZyELVSDFmqpd++aBzZQg@mail.gmail.com/
Suggested-by: Vincent MAILHOL <mailhol.vincent@wanadoo.fr>
Signed-off-by: Frank Jungclaus <frank.jungclaus@esd.eu>
---
 drivers/net/can/usb/esd_usb.c | 33 +++++++++++++--------------------
 1 file changed, 13 insertions(+), 20 deletions(-)

Comments

Vincent Mailhol May 21, 2023, 9:16 a.m. UTC | #1 
Thanks for the patch.

On Sat. 20 May 2023 at 04:57, Frank Jungclaus <frank.jungclaus@esd.eu> wrote:
> Replace the macros used to initialize the members of struct
> can_bittiming_const with direct values. Then also use those struct
> members to do the calculations in esd_usb2_set_bittiming().
>
> Link: https://lore.kernel.org/all/CAMZ6RqLaDNy-fZ2G0+QMhUEckkXLL+ZyELVSDFmqpd++aBzZQg@mail.gmail.com/
> Suggested-by: Vincent MAILHOL <mailhol.vincent@wanadoo.fr>
> Signed-off-by: Frank Jungclaus <frank.jungclaus@esd.eu>
> ---
>  drivers/net/can/usb/esd_usb.c | 33 +++++++++++++--------------------
>  1 file changed, 13 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/net/can/usb/esd_usb.c b/drivers/net/can/usb/esd_usb.c
> index 32354cfdf151..2eecf352ec47 100644
> --- a/drivers/net/can/usb/esd_usb.c
> +++ b/drivers/net/can/usb/esd_usb.c
> @@ -60,18 +60,10 @@ MODULE_LICENSE("GPL v2");
>  #define ESD_USB_NO_BAUDRATE    GENMASK(30, 0) /* bit rate unconfigured */
>
>  /* bit timing CAN-USB/2 */
> -#define ESD_USB2_TSEG1_MIN     1
> -#define ESD_USB2_TSEG1_MAX     16
>  #define ESD_USB2_TSEG1_SHIFT   16
> -#define ESD_USB2_TSEG2_MIN     1
> -#define ESD_USB2_TSEG2_MAX     8
>  #define ESD_USB2_TSEG2_SHIFT   20
> -#define ESD_USB2_SJW_MAX       4
>  #define ESD_USB2_SJW_SHIFT     14
>  #define ESD_USBM_SJW_SHIFT     24
> -#define ESD_USB2_BRP_MIN       1
> -#define ESD_USB2_BRP_MAX       1024
> -#define ESD_USB2_BRP_INC       1
>  #define ESD_USB2_3_SAMPLES     BIT(23)
>
>  /* esd IDADD message */
> @@ -909,19 +901,20 @@ static const struct ethtool_ops esd_usb_ethtool_ops = {
>
>  static const struct can_bittiming_const esd_usb2_bittiming_const = {
>         .name = "esd_usb2",
> -       .tseg1_min = ESD_USB2_TSEG1_MIN,
> -       .tseg1_max = ESD_USB2_TSEG1_MAX,
> -       .tseg2_min = ESD_USB2_TSEG2_MIN,
> -       .tseg2_max = ESD_USB2_TSEG2_MAX,
> -       .sjw_max = ESD_USB2_SJW_MAX,
> -       .brp_min = ESD_USB2_BRP_MIN,
> -       .brp_max = ESD_USB2_BRP_MAX,
> -       .brp_inc = ESD_USB2_BRP_INC,
> +       .tseg1_min = 1,
> +       .tseg1_max = 16,
> +       .tseg2_min = 1,
> +       .tseg2_max = 8,
> +       .sjw_max = 4,
> +       .brp_min = 1,
> +       .brp_max = 1024,
> +       .brp_inc = 1,
>  };
>
>  static int esd_usb2_set_bittiming(struct net_device *netdev)
>  {
>         struct esd_usb_net_priv *priv = netdev_priv(netdev);
> +       const struct can_bittiming_const *btc = priv->can.bittiming_const;

I initially suggested doing:

          const struct can_bittiming_const *btc = priv->can.bittiming_const;

But now that I think again about it, doing:

          const struct can_bittiming_const *btc = &esd_usb2_bittiming_const;

is slightly better as it will allow the compiler to fold the integer
constant expressions such as btc->brp_max - 1. The compiler is not
smart enough to figure out what values are held in
priv->can.bittiming_const at compile time.

Sorry for not figuring this the first time.

>         struct can_bittiming *bt = &priv->can.bittiming;
>         union esd_usb_msg *msg;
>         int err;
> @@ -932,7 +925,7 @@ static int esd_usb2_set_bittiming(struct net_device *netdev)
>         if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
>                 canbtr |= ESD_USB_LOM;
>
> -       canbtr |= (bt->brp - 1) & (ESD_USB2_BRP_MAX - 1);
> +       canbtr |= (bt->brp - 1) & (btc->brp_max - 1);
>
>         if (le16_to_cpu(priv->usb->udev->descriptor.idProduct) ==
>             USB_CANUSBM_PRODUCT_ID)
> @@ -940,12 +933,12 @@ static int esd_usb2_set_bittiming(struct net_device *netdev)
>         else
>                 sjw_shift = ESD_USB2_SJW_SHIFT;
>
> -       canbtr |= ((bt->sjw - 1) & (ESD_USB2_SJW_MAX - 1))
> +       canbtr |= ((bt->sjw - 1) & (btc->sjw_max - 1))
>                 << sjw_shift;
>         canbtr |= ((bt->prop_seg + bt->phase_seg1 - 1)
> -                  & (ESD_USB2_TSEG1_MAX - 1))
> +                  & (btc->tseg1_max - 1))
>                 << ESD_USB2_TSEG1_SHIFT;
> -       canbtr |= ((bt->phase_seg2 - 1) & (ESD_USB2_TSEG2_MAX - 1))
> +       canbtr |= ((bt->phase_seg2 - 1) & (btc->tseg2_max - 1))
>                 << ESD_USB2_TSEG2_SHIFT;
>         if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
>                 canbtr |= ESD_USB2_3_SAMPLES;
> --
> 2.25.1
>
Marc Kleine-Budde May 22, 2023, 8:19 a.m. UTC | #2 
On 21.05.2023 18:16:17, Vincent MAILHOL wrote:
> Thanks for the patch.
> 
> On Sat. 20 May 2023 at 04:57, Frank Jungclaus <frank.jungclaus@esd.eu> wrote:
> > Replace the macros used to initialize the members of struct
> > can_bittiming_const with direct values. Then also use those struct
> > members to do the calculations in esd_usb2_set_bittiming().
> >
> > Link: https://lore.kernel.org/all/CAMZ6RqLaDNy-fZ2G0+QMhUEckkXLL+ZyELVSDFmqpd++aBzZQg@mail.gmail.com/
> > Suggested-by: Vincent MAILHOL <mailhol.vincent@wanadoo.fr>
> > Signed-off-by: Frank Jungclaus <frank.jungclaus@esd.eu>
> > ---
> >  drivers/net/can/usb/esd_usb.c | 33 +++++++++++++--------------------
> >  1 file changed, 13 insertions(+), 20 deletions(-)
> >
> > diff --git a/drivers/net/can/usb/esd_usb.c b/drivers/net/can/usb/esd_usb.c
> > index 32354cfdf151..2eecf352ec47 100644
> > --- a/drivers/net/can/usb/esd_usb.c
> > +++ b/drivers/net/can/usb/esd_usb.c
> > @@ -60,18 +60,10 @@ MODULE_LICENSE("GPL v2");
> >  #define ESD_USB_NO_BAUDRATE    GENMASK(30, 0) /* bit rate unconfigured */
> >
> >  /* bit timing CAN-USB/2 */
> > -#define ESD_USB2_TSEG1_MIN     1
> > -#define ESD_USB2_TSEG1_MAX     16
> >  #define ESD_USB2_TSEG1_SHIFT   16
> > -#define ESD_USB2_TSEG2_MIN     1
> > -#define ESD_USB2_TSEG2_MAX     8
> >  #define ESD_USB2_TSEG2_SHIFT   20
> > -#define ESD_USB2_SJW_MAX       4
> >  #define ESD_USB2_SJW_SHIFT     14
> >  #define ESD_USBM_SJW_SHIFT     24
> > -#define ESD_USB2_BRP_MIN       1
> > -#define ESD_USB2_BRP_MAX       1024
> > -#define ESD_USB2_BRP_INC       1
> >  #define ESD_USB2_3_SAMPLES     BIT(23)
> >
> >  /* esd IDADD message */
> > @@ -909,19 +901,20 @@ static const struct ethtool_ops esd_usb_ethtool_ops = {
> >
> >  static const struct can_bittiming_const esd_usb2_bittiming_const = {
> >         .name = "esd_usb2",
> > -       .tseg1_min = ESD_USB2_TSEG1_MIN,
> > -       .tseg1_max = ESD_USB2_TSEG1_MAX,
> > -       .tseg2_min = ESD_USB2_TSEG2_MIN,
> > -       .tseg2_max = ESD_USB2_TSEG2_MAX,
> > -       .sjw_max = ESD_USB2_SJW_MAX,
> > -       .brp_min = ESD_USB2_BRP_MIN,
> > -       .brp_max = ESD_USB2_BRP_MAX,
> > -       .brp_inc = ESD_USB2_BRP_INC,
> > +       .tseg1_min = 1,
> > +       .tseg1_max = 16,
> > +       .tseg2_min = 1,
> > +       .tseg2_max = 8,
> > +       .sjw_max = 4,
> > +       .brp_min = 1,
> > +       .brp_max = 1024,
> > +       .brp_inc = 1,
> >  };
> >
> >  static int esd_usb2_set_bittiming(struct net_device *netdev)
> >  {
> >         struct esd_usb_net_priv *priv = netdev_priv(netdev);
> > +       const struct can_bittiming_const *btc = priv->can.bittiming_const;
> 
> I initially suggested doing:
> 
>           const struct can_bittiming_const *btc = priv->can.bittiming_const;
> 
> But now that I think again about it, doing:
> 
>           const struct can_bittiming_const *btc = &esd_usb2_bittiming_const;
> 
> is slightly better as it will allow the compiler to fold the integer
> constant expressions such as btc->brp_max - 1. The compiler is not
> smart enough to figure out what values are held in
> priv->can.bittiming_const at compile time.
> 
> Sorry for not figuring this the first time.

Good suggestion! Fixed up while applying.

regards,
Marc
diff mbox series

Patch

diff --git a/drivers/net/can/usb/esd_usb.c b/drivers/net/can/usb/esd_usb.c
index 32354cfdf151..2eecf352ec47 100644
--- a/drivers/net/can/usb/esd_usb.c
+++ b/drivers/net/can/usb/esd_usb.c
@@ -60,18 +60,10 @@  MODULE_LICENSE("GPL v2");
 #define ESD_USB_NO_BAUDRATE	GENMASK(30, 0) /* bit rate unconfigured */
 
 /* bit timing CAN-USB/2 */
-#define ESD_USB2_TSEG1_MIN	1
-#define ESD_USB2_TSEG1_MAX	16
 #define ESD_USB2_TSEG1_SHIFT	16
-#define ESD_USB2_TSEG2_MIN	1
-#define ESD_USB2_TSEG2_MAX	8
 #define ESD_USB2_TSEG2_SHIFT	20
-#define ESD_USB2_SJW_MAX	4
 #define ESD_USB2_SJW_SHIFT	14
 #define ESD_USBM_SJW_SHIFT	24
-#define ESD_USB2_BRP_MIN	1
-#define ESD_USB2_BRP_MAX	1024
-#define ESD_USB2_BRP_INC	1
 #define ESD_USB2_3_SAMPLES	BIT(23)
 
 /* esd IDADD message */
@@ -909,19 +901,20 @@  static const struct ethtool_ops esd_usb_ethtool_ops = {
 
 static const struct can_bittiming_const esd_usb2_bittiming_const = {
 	.name = "esd_usb2",
-	.tseg1_min = ESD_USB2_TSEG1_MIN,
-	.tseg1_max = ESD_USB2_TSEG1_MAX,
-	.tseg2_min = ESD_USB2_TSEG2_MIN,
-	.tseg2_max = ESD_USB2_TSEG2_MAX,
-	.sjw_max = ESD_USB2_SJW_MAX,
-	.brp_min = ESD_USB2_BRP_MIN,
-	.brp_max = ESD_USB2_BRP_MAX,
-	.brp_inc = ESD_USB2_BRP_INC,
+	.tseg1_min = 1,
+	.tseg1_max = 16,
+	.tseg2_min = 1,
+	.tseg2_max = 8,
+	.sjw_max = 4,
+	.brp_min = 1,
+	.brp_max = 1024,
+	.brp_inc = 1,
 };
 
 static int esd_usb2_set_bittiming(struct net_device *netdev)
 {
 	struct esd_usb_net_priv *priv = netdev_priv(netdev);
+	const struct can_bittiming_const *btc = priv->can.bittiming_const;
 	struct can_bittiming *bt = &priv->can.bittiming;
 	union esd_usb_msg *msg;
 	int err;
@@ -932,7 +925,7 @@  static int esd_usb2_set_bittiming(struct net_device *netdev)
 	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
 		canbtr |= ESD_USB_LOM;
 
-	canbtr |= (bt->brp - 1) & (ESD_USB2_BRP_MAX - 1);
+	canbtr |= (bt->brp - 1) & (btc->brp_max - 1);
 
 	if (le16_to_cpu(priv->usb->udev->descriptor.idProduct) ==
 	    USB_CANUSBM_PRODUCT_ID)
@@ -940,12 +933,12 @@  static int esd_usb2_set_bittiming(struct net_device *netdev)
 	else
 		sjw_shift = ESD_USB2_SJW_SHIFT;
 
-	canbtr |= ((bt->sjw - 1) & (ESD_USB2_SJW_MAX - 1))
+	canbtr |= ((bt->sjw - 1) & (btc->sjw_max - 1))
 		<< sjw_shift;
 	canbtr |= ((bt->prop_seg + bt->phase_seg1 - 1)
-		   & (ESD_USB2_TSEG1_MAX - 1))
+		   & (btc->tseg1_max - 1))
 		<< ESD_USB2_TSEG1_SHIFT;
-	canbtr |= ((bt->phase_seg2 - 1) & (ESD_USB2_TSEG2_MAX - 1))
+	canbtr |= ((bt->phase_seg2 - 1) & (btc->tseg2_max - 1))
 		<< ESD_USB2_TSEG2_SHIFT;
 	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 		canbtr |= ESD_USB2_3_SAMPLES;