[PATCH 1/4] drm/radeon/dp: handle zero sized i2c over aux transactions
On Fri, 04 Apr 2014, Alex Deucher wrote:
> Needed for proper i2c over aux handling for certain
> monitors and configurations (e.g., dp bridges or
> adapters).
>
> Signed-off-by: Alex Deucher
> ---
> drivers/gpu/drm/radeon/atombios_dp.c | 15 +++
> 1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/atombios_dp.c
> b/drivers/gpu/drm/radeon/atombios_dp.c
> index 8b0ab17..e914008 100644
> --- a/drivers/gpu/drm/radeon/atombios_dp.c
> +++ b/drivers/gpu/drm/radeon/atombios_dp.c
> @@ -143,6 +143,7 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan
> *chan,
> }
>
> #define HEADER_SIZE 4
> +#define BARE_ADDRESS_SIZE 3
>
> static ssize_t
> radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
> @@ -160,13 +161,16 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
> drm_dp_aux_msg *msg)
> tx_buf[0] = msg->address & 0xff;
> tx_buf[1] = msg->address >> 8;
> tx_buf[2] = msg->request << 4;
> - tx_buf[3] = msg->size - 1;
> + tx_buf[3] = msg->size ? (msg->size - 1) : 0;
>
> switch (msg->request & ~DP_AUX_I2C_MOT) {
> case DP_AUX_NATIVE_WRITE:
> case DP_AUX_I2C_WRITE:
> tx_size = HEADER_SIZE + msg->size;
> - tx_buf[3] |= tx_size << 4;
> + if (msg->size == 0)
> + tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
> + else
> + tx_buf[3] |= tx_size << 4;
> memcpy(tx_buf + HEADER_SIZE, msg->buffer, msg->size);
> ret = radeon_process_aux_ch(chan,
> tx_buf, tx_size, NULL, 0, delay,
> );
I think your tz_size and tx_buf[3] are confused. Shouldn't you only send
3 bytes of tx_buf when msg->size == 0?
Disclaimer, I don't know anything about your hw and all that... :)
BR,
Jani.
> @@ -177,7 +181,10 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
> drm_dp_aux_msg *msg)
> case DP_AUX_NATIVE_READ:
> case DP_AUX_I2C_READ:
> tx_size = HEADER_SIZE;
> - tx_buf[3] |= tx_size << 4;
> + if (msg->size == 0)
> + tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
> + else
> + tx_buf[3] |= tx_size << 4;
> ret = radeon_process_aux_ch(chan,
> tx_buf, tx_size, msg->buffer,
> msg->size, delay, );
> break;
> @@ -186,7 +193,7 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
> drm_dp_aux_msg *msg)
> break;
> }
>
> - if (ret > 0)
> + if (ret >= 0)
> msg->reply = ack >> 4;
>
> return ret;
> --
> 1.8.3.1
>
--
Jani Nikula, Intel Open Source Technology Center
[PATCH 1/4] drm/radeon/dp: handle zero sized i2c over aux transactions (v2)
Needed for proper i2c over aux handling for certain
monitors and configurations (e.g., dp bridges or
adapters).
v2: add comments clarifying tx_size setting.
Signed-off-by: Alex Deucher
---
drivers/gpu/drm/radeon/atombios_dp.c | 23 ++-
1 file changed, 18 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/radeon/atombios_dp.c
b/drivers/gpu/drm/radeon/atombios_dp.c
index 8b0ab17..e448304 100644
--- a/drivers/gpu/drm/radeon/atombios_dp.c
+++ b/drivers/gpu/drm/radeon/atombios_dp.c
@@ -142,7 +142,8 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan
*chan,
return recv_bytes;
}
-#define HEADER_SIZE 4
+#define BARE_ADDRESS_SIZE 3
+#define HEADER_SIZE (BARE_ADDRESS_SIZE + 1)
static ssize_t
radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
@@ -160,13 +161,19 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
drm_dp_aux_msg *msg)
tx_buf[0] = msg->address & 0xff;
tx_buf[1] = msg->address >> 8;
tx_buf[2] = msg->request << 4;
- tx_buf[3] = msg->size - 1;
+ tx_buf[3] = msg->size ? (msg->size - 1) : 0;
switch (msg->request & ~DP_AUX_I2C_MOT) {
case DP_AUX_NATIVE_WRITE:
case DP_AUX_I2C_WRITE:
+ /* tx_size needs to be 4 even for bare address packets since
the atom
+* table needs the info in tx_buf[3].
+*/
tx_size = HEADER_SIZE + msg->size;
- tx_buf[3] |= tx_size << 4;
+ if (msg->size == 0)
+ tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
+ else
+ tx_buf[3] |= tx_size << 4;
memcpy(tx_buf + HEADER_SIZE, msg->buffer, msg->size);
ret = radeon_process_aux_ch(chan,
tx_buf, tx_size, NULL, 0, delay,
);
@@ -176,8 +183,14 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
drm_dp_aux_msg *msg)
break;
case DP_AUX_NATIVE_READ:
case DP_AUX_I2C_READ:
+ /* tx_size needs to be 4 even for bare address packets since
the atom
+* table needs the info in tx_buf[3].
+*/
tx_size = HEADER_SIZE;
- tx_buf[3] |= tx_size << 4;
+ if (msg->size == 0)
+ tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
+ else
+ tx_buf[3] |= tx_size << 4;
ret = radeon_process_aux_ch(chan,
tx_buf, tx_size, msg->buffer,
msg->size, delay, );
break;
@@ -186,7 +199,7 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
drm_dp_aux_msg *msg)
break;
}
- if (ret > 0)
+ if (ret >= 0)
msg->reply = ack >> 4;
return ret;
--
1.8.3.1
[PATCH 1/4] drm/radeon/dp: handle zero sized i2c over aux transactions
On Mon, Apr 7, 2014 at 9:24 AM, Alex Deucher wrote:
> On Mon, Apr 7, 2014 at 3:57 AM, Jani Nikula
> wrote:
>> On Fri, 04 Apr 2014, Alex Deucher wrote:
>>> Needed for proper i2c over aux handling for certain
>>> monitors and configurations (e.g., dp bridges or
>>> adapters).
>>>
>>> Signed-off-by: Alex Deucher
>>> ---
>>> drivers/gpu/drm/radeon/atombios_dp.c | 15 +++
>>> 1 file changed, 11 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/radeon/atombios_dp.c
>>> b/drivers/gpu/drm/radeon/atombios_dp.c
>>> index 8b0ab17..e914008 100644
>>> --- a/drivers/gpu/drm/radeon/atombios_dp.c
>>> +++ b/drivers/gpu/drm/radeon/atombios_dp.c
>>> @@ -143,6 +143,7 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan
>>> *chan,
>>> }
>>>
>>> #define HEADER_SIZE 4
>>> +#define BARE_ADDRESS_SIZE 3
>>>
>>> static ssize_t
>>> radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
>>> @@ -160,13 +161,16 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
>>> drm_dp_aux_msg *msg)
>>> tx_buf[0] = msg->address & 0xff;
>>> tx_buf[1] = msg->address >> 8;
>>> tx_buf[2] = msg->request << 4;
>>> - tx_buf[3] = msg->size - 1;
>>> + tx_buf[3] = msg->size ? (msg->size - 1) : 0;
>>>
>>> switch (msg->request & ~DP_AUX_I2C_MOT) {
>>> case DP_AUX_NATIVE_WRITE:
>>> case DP_AUX_I2C_WRITE:
>>> tx_size = HEADER_SIZE + msg->size;
>>> - tx_buf[3] |= tx_size << 4;
>>> + if (msg->size == 0)
>>> + tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
>>> + else
>>> + tx_buf[3] |= tx_size << 4;
>>> memcpy(tx_buf + HEADER_SIZE, msg->buffer, msg->size);
>>> ret = radeon_process_aux_ch(chan,
>>> tx_buf, tx_size, NULL, 0, delay,
>>> );
>>
>> I think your tz_size and tx_buf[3] are confused. Shouldn't you only send
>> 3 bytes of tx_buf when msg->size == 0?
>>
>> Disclaimer, I don't know anything about your hw and all that... :)
>
> It doesn't really matter. The hw only cares about the size specified
> in tx_buf[3]. tx_size is only used to determine how much data to the
> buffer used by the atom table. We end up copying an extra byte that
> never gets used. I suppose I should fix it up for clarify.
Actually, I was wrong. We need all 4 bytes of the tx_buf, but the hw
only sends 3 based on the size specified in tx_buf[3]. so the code is
correct as is.
Alex
>
> Alex
>
>>
>> BR,
>> Jani.
>>
>>
>>> @@ -177,7 +181,10 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
>>> drm_dp_aux_msg *msg)
>>> case DP_AUX_NATIVE_READ:
>>> case DP_AUX_I2C_READ:
>>> tx_size = HEADER_SIZE;
>>> - tx_buf[3] |= tx_size << 4;
>>> + if (msg->size == 0)
>>> + tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
>>> + else
>>> + tx_buf[3] |= tx_size << 4;
>>> ret = radeon_process_aux_ch(chan,
>>> tx_buf, tx_size, msg->buffer,
>>> msg->size, delay, );
>>> break;
>>> @@ -186,7 +193,7 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
>>> drm_dp_aux_msg *msg)
>>> break;
>>> }
>>>
>>> - if (ret > 0)
>>> + if (ret >= 0)
>>> msg->reply = ack >> 4;
>>>
>>> return ret;
>>> --
>>> 1.8.3.1
>>>
>>
>> --
>> Jani Nikula, Intel Open Source Technology Center
[PATCH 1/4] drm/radeon/dp: handle zero sized i2c over aux transactions
On Mon, Apr 7, 2014 at 3:57 AM, Jani Nikula
wrote:
> On Fri, 04 Apr 2014, Alex Deucher wrote:
>> Needed for proper i2c over aux handling for certain
>> monitors and configurations (e.g., dp bridges or
>> adapters).
>>
>> Signed-off-by: Alex Deucher
>> ---
>> drivers/gpu/drm/radeon/atombios_dp.c | 15 +++
>> 1 file changed, 11 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/radeon/atombios_dp.c
>> b/drivers/gpu/drm/radeon/atombios_dp.c
>> index 8b0ab17..e914008 100644
>> --- a/drivers/gpu/drm/radeon/atombios_dp.c
>> +++ b/drivers/gpu/drm/radeon/atombios_dp.c
>> @@ -143,6 +143,7 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan
>> *chan,
>> }
>>
>> #define HEADER_SIZE 4
>> +#define BARE_ADDRESS_SIZE 3
>>
>> static ssize_t
>> radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
>> @@ -160,13 +161,16 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
>> drm_dp_aux_msg *msg)
>> tx_buf[0] = msg->address & 0xff;
>> tx_buf[1] = msg->address >> 8;
>> tx_buf[2] = msg->request << 4;
>> - tx_buf[3] = msg->size - 1;
>> + tx_buf[3] = msg->size ? (msg->size - 1) : 0;
>>
>> switch (msg->request & ~DP_AUX_I2C_MOT) {
>> case DP_AUX_NATIVE_WRITE:
>> case DP_AUX_I2C_WRITE:
>> tx_size = HEADER_SIZE + msg->size;
>> - tx_buf[3] |= tx_size << 4;
>> + if (msg->size == 0)
>> + tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
>> + else
>> + tx_buf[3] |= tx_size << 4;
>> memcpy(tx_buf + HEADER_SIZE, msg->buffer, msg->size);
>> ret = radeon_process_aux_ch(chan,
>> tx_buf, tx_size, NULL, 0, delay,
>> );
>
> I think your tz_size and tx_buf[3] are confused. Shouldn't you only send
> 3 bytes of tx_buf when msg->size == 0?
>
> Disclaimer, I don't know anything about your hw and all that... :)
It doesn't really matter. The hw only cares about the size specified
in tx_buf[3]. tx_size is only used to determine how much data to the
buffer used by the atom table. We end up copying an extra byte that
never gets used. I suppose I should fix it up for clarify.
Alex
>
> BR,
> Jani.
>
>
>> @@ -177,7 +181,10 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
>> drm_dp_aux_msg *msg)
>> case DP_AUX_NATIVE_READ:
>> case DP_AUX_I2C_READ:
>> tx_size = HEADER_SIZE;
>> - tx_buf[3] |= tx_size << 4;
>> + if (msg->size == 0)
>> + tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
>> + else
>> + tx_buf[3] |= tx_size << 4;
>> ret = radeon_process_aux_ch(chan,
>> tx_buf, tx_size, msg->buffer,
>> msg->size, delay, );
>> break;
>> @@ -186,7 +193,7 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
>> drm_dp_aux_msg *msg)
>> break;
>> }
>>
>> - if (ret > 0)
>> + if (ret >= 0)
>> msg->reply = ack >> 4;
>>
>> return ret;
>> --
>> 1.8.3.1
>>
>
> --
> Jani Nikula, Intel Open Source Technology Center
[PATCH 1/4] drm/radeon/dp: handle zero sized i2c over aux transactions
On Sat, Apr 5, 2014 at 5:25 AM, Christian K?nig
wrote:
> Am 04.04.2014 21:58, schrieb Alex Deucher:
>
>> Needed for proper i2c over aux handling for certain
>> monitors and configurations (e.g., dp bridges or
>> adapters).
>>
>> Signed-off-by: Alex Deucher
>
>
> My planning was that yesterdays pull request is the last one with new
> features. I can't judge how invasive this series is, so should I add it to
> my 3.15 branch and send Dave another pull request or should we wait for
> 3.16?
I'd like to get them into 3.15. They provide a really nice cleanup
for the radeon dp i2c handling.
Alex
>
> Christian.
>
>
>> ---
>> drivers/gpu/drm/radeon/atombios_dp.c | 15 +++
>> 1 file changed, 11 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/radeon/atombios_dp.c
>> b/drivers/gpu/drm/radeon/atombios_dp.c
>> index 8b0ab17..e914008 100644
>> --- a/drivers/gpu/drm/radeon/atombios_dp.c
>> +++ b/drivers/gpu/drm/radeon/atombios_dp.c
>> @@ -143,6 +143,7 @@ static int radeon_process_aux_ch(struct
>> radeon_i2c_chan *chan,
>> }
>> #define HEADER_SIZE 4
>> +#define BARE_ADDRESS_SIZE 3
>> static ssize_t
>> radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg
>> *msg)
>> @@ -160,13 +161,16 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux,
>> struct drm_dp_aux_msg *msg)
>> tx_buf[0] = msg->address & 0xff;
>> tx_buf[1] = msg->address >> 8;
>> tx_buf[2] = msg->request << 4;
>> - tx_buf[3] = msg->size - 1;
>> + tx_buf[3] = msg->size ? (msg->size - 1) : 0;
>> switch (msg->request & ~DP_AUX_I2C_MOT) {
>> case DP_AUX_NATIVE_WRITE:
>> case DP_AUX_I2C_WRITE:
>> tx_size = HEADER_SIZE + msg->size;
>> - tx_buf[3] |= tx_size << 4;
>> + if (msg->size == 0)
>> + tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
>> + else
>> + tx_buf[3] |= tx_size << 4;
>> memcpy(tx_buf + HEADER_SIZE, msg->buffer, msg->size);
>> ret = radeon_process_aux_ch(chan,
>> tx_buf, tx_size, NULL, 0,
>> delay, );
>> @@ -177,7 +181,10 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
>> drm_dp_aux_msg *msg)
>> case DP_AUX_NATIVE_READ:
>> case DP_AUX_I2C_READ:
>> tx_size = HEADER_SIZE;
>> - tx_buf[3] |= tx_size << 4;
>> + if (msg->size == 0)
>> + tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
>> + else
>> + tx_buf[3] |= tx_size << 4;
>> ret = radeon_process_aux_ch(chan,
>> tx_buf, tx_size, msg->buffer,
>> msg->size, delay, );
>> break;
>> @@ -186,7 +193,7 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
>> drm_dp_aux_msg *msg)
>> break;
>> }
>> - if (ret > 0)
>> + if (ret >= 0)
>> msg->reply = ack >> 4;
>> return ret;
>
>
[PATCH 1/4] drm/radeon/dp: handle zero sized i2c over aux transactions
On Sat, Apr 05, 2014 at 11:25:01AM +0200, Christian K?nig wrote: > Am 04.04.2014 21:58, schrieb Alex Deucher: > >Needed for proper i2c over aux handling for certain > >monitors and configurations (e.g., dp bridges or > >adapters). > > > >Signed-off-by: Alex Deucher > > My planning was that yesterdays pull request is the last one with > new features. I can't judge how invasive this series is, so should I > add it to my 3.15 branch and send Dave another pull request or > should we wait for 3.16? At least the two patches for the dp aux helper code should go into 3.15 since they fix a behavioral regression in i915, too. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch
[PATCH 1/4] drm/radeon/dp: handle zero sized i2c over aux transactions
Am 04.04.2014 21:58, schrieb Alex Deucher:
> Needed for proper i2c over aux handling for certain
> monitors and configurations (e.g., dp bridges or
> adapters).
>
> Signed-off-by: Alex Deucher
My planning was that yesterdays pull request is the last one with new
features. I can't judge how invasive this series is, so should I add it
to my 3.15 branch and send Dave another pull request or should we wait
for 3.16?
Christian.
> ---
> drivers/gpu/drm/radeon/atombios_dp.c | 15 +++
> 1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/atombios_dp.c
> b/drivers/gpu/drm/radeon/atombios_dp.c
> index 8b0ab17..e914008 100644
> --- a/drivers/gpu/drm/radeon/atombios_dp.c
> +++ b/drivers/gpu/drm/radeon/atombios_dp.c
> @@ -143,6 +143,7 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan
> *chan,
> }
>
> #define HEADER_SIZE 4
> +#define BARE_ADDRESS_SIZE 3
>
> static ssize_t
> radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
> @@ -160,13 +161,16 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
> drm_dp_aux_msg *msg)
> tx_buf[0] = msg->address & 0xff;
> tx_buf[1] = msg->address >> 8;
> tx_buf[2] = msg->request << 4;
> - tx_buf[3] = msg->size - 1;
> + tx_buf[3] = msg->size ? (msg->size - 1) : 0;
>
> switch (msg->request & ~DP_AUX_I2C_MOT) {
> case DP_AUX_NATIVE_WRITE:
> case DP_AUX_I2C_WRITE:
> tx_size = HEADER_SIZE + msg->size;
> - tx_buf[3] |= tx_size << 4;
> + if (msg->size == 0)
> + tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
> + else
> + tx_buf[3] |= tx_size << 4;
> memcpy(tx_buf + HEADER_SIZE, msg->buffer, msg->size);
> ret = radeon_process_aux_ch(chan,
> tx_buf, tx_size, NULL, 0, delay,
> );
> @@ -177,7 +181,10 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
> drm_dp_aux_msg *msg)
> case DP_AUX_NATIVE_READ:
> case DP_AUX_I2C_READ:
> tx_size = HEADER_SIZE;
> - tx_buf[3] |= tx_size << 4;
> + if (msg->size == 0)
> + tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
> + else
> + tx_buf[3] |= tx_size << 4;
> ret = radeon_process_aux_ch(chan,
> tx_buf, tx_size, msg->buffer,
> msg->size, delay, );
> break;
> @@ -186,7 +193,7 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
> drm_dp_aux_msg *msg)
> break;
> }
>
> - if (ret > 0)
> + if (ret >= 0)
> msg->reply = ack >> 4;
>
> return ret;
[PATCH 1/4] drm/radeon/dp: handle zero sized i2c over aux transactions
Needed for proper i2c over aux handling for certain
monitors and configurations (e.g., dp bridges or
adapters).
Signed-off-by: Alex Deucher
---
drivers/gpu/drm/radeon/atombios_dp.c | 15 +++
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/radeon/atombios_dp.c
b/drivers/gpu/drm/radeon/atombios_dp.c
index 8b0ab17..e914008 100644
--- a/drivers/gpu/drm/radeon/atombios_dp.c
+++ b/drivers/gpu/drm/radeon/atombios_dp.c
@@ -143,6 +143,7 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan
*chan,
}
#define HEADER_SIZE 4
+#define BARE_ADDRESS_SIZE 3
static ssize_t
radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
@@ -160,13 +161,16 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
drm_dp_aux_msg *msg)
tx_buf[0] = msg->address & 0xff;
tx_buf[1] = msg->address >> 8;
tx_buf[2] = msg->request << 4;
- tx_buf[3] = msg->size - 1;
+ tx_buf[3] = msg->size ? (msg->size - 1) : 0;
switch (msg->request & ~DP_AUX_I2C_MOT) {
case DP_AUX_NATIVE_WRITE:
case DP_AUX_I2C_WRITE:
tx_size = HEADER_SIZE + msg->size;
- tx_buf[3] |= tx_size << 4;
+ if (msg->size == 0)
+ tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
+ else
+ tx_buf[3] |= tx_size << 4;
memcpy(tx_buf + HEADER_SIZE, msg->buffer, msg->size);
ret = radeon_process_aux_ch(chan,
tx_buf, tx_size, NULL, 0, delay,
);
@@ -177,7 +181,10 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
drm_dp_aux_msg *msg)
case DP_AUX_NATIVE_READ:
case DP_AUX_I2C_READ:
tx_size = HEADER_SIZE;
- tx_buf[3] |= tx_size << 4;
+ if (msg->size == 0)
+ tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
+ else
+ tx_buf[3] |= tx_size << 4;
ret = radeon_process_aux_ch(chan,
tx_buf, tx_size, msg->buffer,
msg->size, delay, );
break;
@@ -186,7 +193,7 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
drm_dp_aux_msg *msg)
break;
}
- if (ret > 0)
+ if (ret >= 0)
msg->reply = ack >> 4;
return ret;
--
1.8.3.1
[PATCH 1/4] drm/radeon/dp: handle zero sized i2c over aux transactions
Needed for proper i2c over aux handling for certain
monitors and configurations (e.g., dp bridges or
adapters).
Signed-off-by: Alex Deucher
---
drivers/gpu/drm/radeon/atombios_dp.c | 15 +++
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/radeon/atombios_dp.c
b/drivers/gpu/drm/radeon/atombios_dp.c
index 8b0ab17..e914008 100644
--- a/drivers/gpu/drm/radeon/atombios_dp.c
+++ b/drivers/gpu/drm/radeon/atombios_dp.c
@@ -143,6 +143,7 @@ static int radeon_process_aux_ch(struct radeon_i2c_chan
*chan,
}
#define HEADER_SIZE 4
+#define BARE_ADDRESS_SIZE 3
static ssize_t
radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
@@ -160,13 +161,16 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
drm_dp_aux_msg *msg)
tx_buf[0] = msg->address & 0xff;
tx_buf[1] = msg->address >> 8;
tx_buf[2] = msg->request << 4;
- tx_buf[3] = msg->size - 1;
+ tx_buf[3] = msg->size ? (msg->size - 1) : 0;
switch (msg->request & ~DP_AUX_I2C_MOT) {
case DP_AUX_NATIVE_WRITE:
case DP_AUX_I2C_WRITE:
tx_size = HEADER_SIZE + msg->size;
- tx_buf[3] |= tx_size << 4;
+ if (msg->size == 0)
+ tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
+ else
+ tx_buf[3] |= tx_size << 4;
memcpy(tx_buf + HEADER_SIZE, msg->buffer, msg->size);
ret = radeon_process_aux_ch(chan,
tx_buf, tx_size, NULL, 0, delay,
);
@@ -177,7 +181,10 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
drm_dp_aux_msg *msg)
case DP_AUX_NATIVE_READ:
case DP_AUX_I2C_READ:
tx_size = HEADER_SIZE;
- tx_buf[3] |= tx_size << 4;
+ if (msg->size == 0)
+ tx_buf[3] |= BARE_ADDRESS_SIZE << 4;
+ else
+ tx_buf[3] |= tx_size << 4;
ret = radeon_process_aux_ch(chan,
tx_buf, tx_size, msg->buffer,
msg->size, delay, );
break;
@@ -186,7 +193,7 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct
drm_dp_aux_msg *msg)
break;
}
- if (ret > 0)
+ if (ret >= 0)
msg->reply = ack >> 4;
return ret;
--
1.8.3.1
