[v3] ucsi_ccg: Refine the UCSI Interrupt handling
Commit Message
From: Sing-Han Chen <singhanc@nvidia.com>
For the CCGx, when the OPM field in the INTR_REG is cleared, then the
CCI data in the PPM is reset.
To align with the CCGx UCSI interface guide, this patch updates the
driver to copy CCI and MESSAGE_IN before clearing UCSI interrupt.
When a new command is sent, the driver will clear the old CCI and
MESSAGE_IN copy.
Finally, clear UCSI_READ_INT before calling complete() to ensure that
the ucsi_ccg_sync_write() would wait for the interrupt handling to
complete.
It prevents the driver from resetting CCI prematurely.
Signed-off-by: Sing-Han Chen <singhanc@nvidia.com>
Signed-off-by: Haotien Hsu <haotienh@nvidia.com>
---
V1->V2
- Fix uninitialized symbol 'cci'
v2->v3
- Remove wrong Reported-by tags
---
drivers/usb/typec/ucsi/ucsi_ccg.c | 86 ++++++++++++++++++++++++++++---
1 file changed, 79 insertions(+), 7 deletions(-)
Comments
On Tue, Jan 03, 2023 at 04:15:31PM +0800, Haotien Hsu wrote:
> From: Sing-Han Chen <singhanc@nvidia.com>
>
> For the CCGx, when the OPM field in the INTR_REG is cleared, then the
> CCI data in the PPM is reset.
>
> To align with the CCGx UCSI interface guide, this patch updates the
> driver to copy CCI and MESSAGE_IN before clearing UCSI interrupt.
> When a new command is sent, the driver will clear the old CCI and
> MESSAGE_IN copy.
>
> Finally, clear UCSI_READ_INT before calling complete() to ensure that
> the ucsi_ccg_sync_write() would wait for the interrupt handling to
> complete.
> It prevents the driver from resetting CCI prematurely.
>
> Signed-off-by: Sing-Han Chen <singhanc@nvidia.com>
> Signed-off-by: Haotien Hsu <haotienh@nvidia.com>
> ---
> V1->V2
> - Fix uninitialized symbol 'cci'
> v2->v3
> - Remove wrong Reported-by tags
> ---
> drivers/usb/typec/ucsi/ucsi_ccg.c | 86 ++++++++++++++++++++++++++++---
> 1 file changed, 79 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/usb/typec/ucsi/ucsi_ccg.c b/drivers/usb/typec/ucsi/ucsi_ccg.c
> index eab3012e1b01..b35a3a97c9fb 100644
> --- a/drivers/usb/typec/ucsi/ucsi_ccg.c
> +++ b/drivers/usb/typec/ucsi/ucsi_ccg.c
> @@ -192,6 +192,12 @@ struct ucsi_ccg_altmode {
> bool checked;
> } __packed;
>
> +#define CCGX_MESSAGE_IN_MAX 4
> +struct op_region {
> + u32 cci;
> + u32 message_in[CCGX_MESSAGE_IN_MAX];
> +};
> +
> struct ucsi_ccg {
> struct device *dev;
> struct ucsi *ucsi;
> @@ -222,6 +228,9 @@ struct ucsi_ccg {
> bool has_multiple_dp;
> struct ucsi_ccg_altmode orig[UCSI_MAX_ALTMODES];
> struct ucsi_ccg_altmode updated[UCSI_MAX_ALTMODES];
> +
> + spinlock_t op_lock;
What does this lock protect? Please document that so that we can verify
if this really is a correct change _AND_ so we know what future changes
need to take the lock or not.
> + struct op_region op_data;
> };
>
> static int ccg_read(struct ucsi_ccg *uc, u16 rab, u8 *data, u32 len)
> @@ -305,12 +314,57 @@ static int ccg_write(struct ucsi_ccg *uc, u16 rab, const u8 *data, u32 len)
> return 0;
> }
>
> +static void ccg_op_region_read(struct ucsi_ccg *uc, unsigned int offset,
> + void *val, size_t val_len)
> +{
> + struct op_region *data = &uc->op_data;
> +
> + spin_lock(&uc->op_lock);
> + if (offset == UCSI_CCI)
> + memcpy(val, &data->cci, val_len);
> + else if (offset == UCSI_MESSAGE_IN)
> + memcpy(val, &data->message_in, val_len);
> + spin_unlock(&uc->op_lock);
> +}
> +
> +static void ccg_op_region_update(struct ucsi_ccg *uc, u32 cci)
> +{
> + u16 reg = CCGX_RAB_UCSI_DATA_BLOCK(UCSI_MESSAGE_IN);
> + struct op_region *data = &uc->op_data;
> + u32 message_in[CCGX_MESSAGE_IN_MAX];
> +
> + if (UCSI_CCI_LENGTH(cci))
> + if (ccg_read(uc, reg, (void *)&message_in,
> + sizeof(message_in))) {
> + dev_err(uc->dev, "failed to read MESSAGE_IN\n");
What can userspace do with this error? Will it be repeated a lot?
thanks,
greg k-h
On 1/6/23 16:10, Greg Kroah-Hartman wrote:
> External email: Use caution opening links or attachments
>
>
> On Tue, Jan 03, 2023 at 04:15:31PM +0800, Haotien Hsu wrote:
>> From: Sing-Han Chen <singhanc@nvidia.com>
>>
>> For the CCGx, when the OPM field in the INTR_REG is cleared, then the
>> CCI data in the PPM is reset.
>>
>> To align with the CCGx UCSI interface guide, this patch updates the
>> driver to copy CCI and MESSAGE_IN before clearing UCSI interrupt.
>> When a new command is sent, the driver will clear the old CCI and
>> MESSAGE_IN copy.
>>
>> Finally, clear UCSI_READ_INT before calling complete() to ensure that
>> the ucsi_ccg_sync_write() would wait for the interrupt handling to
>> complete.
>> It prevents the driver from resetting CCI prematurely.
>>
>> Signed-off-by: Sing-Han Chen <singhanc@nvidia.com>
>> Signed-off-by: Haotien Hsu <haotienh@nvidia.com>
>> ---
>> V1->V2
>> - Fix uninitialized symbol 'cci'
>> v2->v3
>> - Remove wrong Reported-by tags
>> ---
>> drivers/usb/typec/ucsi/ucsi_ccg.c | 86 ++++++++++++++++++++++++++++---
>> 1 file changed, 79 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/usb/typec/ucsi/ucsi_ccg.c b/drivers/usb/typec/ucsi/ucsi_ccg.c
>> index eab3012e1b01..b35a3a97c9fb 100644
>> --- a/drivers/usb/typec/ucsi/ucsi_ccg.c
>> +++ b/drivers/usb/typec/ucsi/ucsi_ccg.c
>> @@ -192,6 +192,12 @@ struct ucsi_ccg_altmode {
>> bool checked;
>> } __packed;
>>
>> +#define CCGX_MESSAGE_IN_MAX 4
>> +struct op_region {
>> + u32 cci;
>> + u32 message_in[CCGX_MESSAGE_IN_MAX];
>> +};
>> +
>> struct ucsi_ccg {
>> struct device *dev;
>> struct ucsi *ucsi;
>> @@ -222,6 +228,9 @@ struct ucsi_ccg {
>> bool has_multiple_dp;
>> struct ucsi_ccg_altmode orig[UCSI_MAX_ALTMODES];
>> struct ucsi_ccg_altmode updated[UCSI_MAX_ALTMODES];
>> +
>> + spinlock_t op_lock;
>
> What does this lock protect? Please document that so that we can verify
> if this really is a correct change _AND_ so we know what future changes
> need to take the lock or not.
>
/* This spinlock protects op_data which includes CCI and MESSAGE_IN that
* will be updated in ISR */
spinlock_t op_lock;
I will add this comment into v4.
>> + struct op_region op_data;
>> };
>>
>> static int ccg_read(struct ucsi_ccg *uc, u16 rab, u8 *data, u32 len)
>> @@ -305,12 +314,57 @@ static int ccg_write(struct ucsi_ccg *uc, u16 rab, const u8 *data, u32 len)
>> return 0;
>> }
>>
>> +static void ccg_op_region_read(struct ucsi_ccg *uc, unsigned int offset,
>> + void *val, size_t val_len)
>> +{
>> + struct op_region *data = &uc->op_data;
>> +
>> + spin_lock(&uc->op_lock);
>> + if (offset == UCSI_CCI)
>> + memcpy(val, &data->cci, val_len);
>> + else if (offset == UCSI_MESSAGE_IN)
>> + memcpy(val, &data->message_in, val_len);
>> + spin_unlock(&uc->op_lock);
>> +}
>> +
>> +static void ccg_op_region_update(struct ucsi_ccg *uc, u32 cci)
>> +{
>> + u16 reg = CCGX_RAB_UCSI_DATA_BLOCK(UCSI_MESSAGE_IN);
>> + struct op_region *data = &uc->op_data;
>> + u32 message_in[CCGX_MESSAGE_IN_MAX];
>> +
>> + if (UCSI_CCI_LENGTH(cci))
>> + if (ccg_read(uc, reg, (void *)&message_in,
>> + sizeof(message_in))) {
>> + dev_err(uc->dev, "failed to read MESSAGE_IN\n");
>
> What can userspace do with this error? Will it be repeated a lot?
>
If driver is okay to read CCI but failed to read MESSAGE_IN, it's an
critical error in CCGx and in this situation, this log could repeat a lot.
We don't seem to have a good way to help this situation from userspace.
In our case, the failure on ccg_read() is mostly because of the I2C
issue. When there is an I2C issue between CCGx & Tegra, the failure is
more likely happening in the earlier stage (e.g., INTR read or CCI read).
Please let me know if you have more questions and concerns.
> thanks,
>
> greg k-h
>
@@ -192,6 +192,12 @@ struct ucsi_ccg_altmode {
bool checked;
} __packed;
+#define CCGX_MESSAGE_IN_MAX 4
+struct op_region {
+ u32 cci;
+ u32 message_in[CCGX_MESSAGE_IN_MAX];
+};
+
struct ucsi_ccg {
struct device *dev;
struct ucsi *ucsi;
@@ -222,6 +228,9 @@ struct ucsi_ccg {
bool has_multiple_dp;
struct ucsi_ccg_altmode orig[UCSI_MAX_ALTMODES];
struct ucsi_ccg_altmode updated[UCSI_MAX_ALTMODES];
+
+ spinlock_t op_lock;
+ struct op_region op_data;
};
static int ccg_read(struct ucsi_ccg *uc, u16 rab, u8 *data, u32 len)
@@ -305,12 +314,57 @@ static int ccg_write(struct ucsi_ccg *uc, u16 rab, const u8 *data, u32 len)
return 0;
}
+static void ccg_op_region_read(struct ucsi_ccg *uc, unsigned int offset,
+ void *val, size_t val_len)
+{
+ struct op_region *data = &uc->op_data;
+
+ spin_lock(&uc->op_lock);
+ if (offset == UCSI_CCI)
+ memcpy(val, &data->cci, val_len);
+ else if (offset == UCSI_MESSAGE_IN)
+ memcpy(val, &data->message_in, val_len);
+ spin_unlock(&uc->op_lock);
+}
+
+static void ccg_op_region_update(struct ucsi_ccg *uc, u32 cci)
+{
+ u16 reg = CCGX_RAB_UCSI_DATA_BLOCK(UCSI_MESSAGE_IN);
+ struct op_region *data = &uc->op_data;
+ u32 message_in[CCGX_MESSAGE_IN_MAX];
+
+ if (UCSI_CCI_LENGTH(cci))
+ if (ccg_read(uc, reg, (void *)&message_in,
+ sizeof(message_in))) {
+ dev_err(uc->dev, "failed to read MESSAGE_IN\n");
+ return;
+ }
+
+ spin_lock(&uc->op_lock);
+ memcpy(&data->cci, &cci, sizeof(cci));
+ if (UCSI_CCI_LENGTH(cci))
+ memcpy(&data->message_in, &message_in, sizeof(message_in));
+ spin_unlock(&uc->op_lock);
+}
+
+static void ccg_op_region_clean(struct ucsi_ccg *uc)
+{
+ struct op_region *data = &uc->op_data;
+
+ spin_lock(&uc->op_lock);
+ memset(&data->cci, 0, sizeof(data->cci));
+ memset(&data->message_in, 0, sizeof(data->message_in));
+ spin_unlock(&uc->op_lock);
+}
+
static int ucsi_ccg_init(struct ucsi_ccg *uc)
{
unsigned int count = 10;
u8 data;
int status;
+ spin_lock_init(&uc->op_lock);
+
data = CCGX_RAB_UCSI_CONTROL_STOP;
status = ccg_write(uc, CCGX_RAB_UCSI_CONTROL, &data, sizeof(data));
if (status < 0)
@@ -520,9 +574,13 @@ static int ucsi_ccg_read(struct ucsi *ucsi, unsigned int offset,
u16 reg = CCGX_RAB_UCSI_DATA_BLOCK(offset);
struct ucsi_capability *cap;
struct ucsi_altmode *alt;
- int ret;
+ int ret = 0;
+
+ if ((offset == UCSI_CCI) || (offset == UCSI_MESSAGE_IN))
+ ccg_op_region_read(uc, offset, val, val_len);
+ else
+ ret = ccg_read(uc, reg, val, val_len);
- ret = ccg_read(uc, reg, val, val_len);
if (ret)
return ret;
@@ -559,9 +617,13 @@ static int ucsi_ccg_read(struct ucsi *ucsi, unsigned int offset,
static int ucsi_ccg_async_write(struct ucsi *ucsi, unsigned int offset,
const void *val, size_t val_len)
{
+ struct ucsi_ccg *uc = ucsi_get_drvdata(ucsi);
u16 reg = CCGX_RAB_UCSI_DATA_BLOCK(offset);
- return ccg_write(ucsi_get_drvdata(ucsi), reg, val, val_len);
+ if (offset == UCSI_CONTROL)
+ ccg_op_region_clean(uc);
+
+ return ccg_write(uc, reg, val, val_len);
}
static int ucsi_ccg_sync_write(struct ucsi *ucsi, unsigned int offset,
@@ -616,12 +678,17 @@ static irqreturn_t ccg_irq_handler(int irq, void *data)
struct ucsi_ccg *uc = data;
u8 intr_reg;
u32 cci;
- int ret;
+ int ret = 0;
ret = ccg_read(uc, CCGX_RAB_INTR_REG, &intr_reg, sizeof(intr_reg));
if (ret)
return ret;
+ if (!intr_reg)
+ return IRQ_HANDLED;
+ else if (!(intr_reg & UCSI_READ_INT))
+ goto err_clear_irq;
+
ret = ccg_read(uc, reg, (void *)&cci, sizeof(cci));
if (ret)
goto err_clear_irq;
@@ -629,13 +696,18 @@ static irqreturn_t ccg_irq_handler(int irq, void *data)
if (UCSI_CCI_CONNECTOR(cci))
ucsi_connector_change(uc->ucsi, UCSI_CCI_CONNECTOR(cci));
- if (test_bit(DEV_CMD_PENDING, &uc->flags) &&
- cci & (UCSI_CCI_ACK_COMPLETE | UCSI_CCI_COMMAND_COMPLETE))
- complete(&uc->complete);
+ /* As per CCGx UCSI interface guide, copy CCI and MESSAGE_IN
+ * to the OpRegion before clear the UCSI interrupt
+ */
+ ccg_op_region_update(uc, cci);
err_clear_irq:
ccg_write(uc, CCGX_RAB_INTR_REG, &intr_reg, sizeof(intr_reg));
+ if (!ret && test_bit(DEV_CMD_PENDING, &uc->flags) &&
+ cci & (UCSI_CCI_ACK_COMPLETE | UCSI_CCI_COMMAND_COMPLETE))
+ complete(&uc->complete);
+
return IRQ_HANDLED;
}