[PATCH V3] drm: edid: add support for E-DDC
On Fri, Aug 24, 2012 at 02:56:50PM +0530, Shirish S wrote:
> The current logic for probing ddc is limited to
> 2 blocks (256 bytes), this patch adds support
> for the 4 block (512) data.
>
> To do this, a single 8-bit segment index is
> passed to the display via the I2C address 30h.
> Data from the selected segment is then immediately
> read via the regular DDC2 address using a repeated
> I2C 'START' signal.
>
> Signed-off-by: Shirish S
> ---
> drivers/gpu/drm/drm_edid.c | 83 ---
> 1 files changed, 62 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index a8743c3..a10a130 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -254,6 +254,8 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter,
> unsigned char *buf,
> int block, int len)
> {
> unsigned char start = block * EDID_LENGTH;
> + unsigned char segment = block >> 1;
> + unsigned short segFlags = segment ? 0 : I2C_M_IGNORE_NAK;
You can inline segFlags to the only place it's used.
> int ret, retries = 5;
>
> /* The core i2c driver will automatically retry the transfer if the
> @@ -262,29 +264,68 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter,
> unsigned char *buf,
>* generate spurious NAKs and timeouts. Retrying the transfer
>* of the individual block a few times seems to overcome this.
>*/
> - do {
> - struct i2c_msg msgs[] = {
> - {
> - .addr = DDC_ADDR,
> - .flags = 0,
> - .len= 1,
> - .buf= &start,
> - }, {
> - .addr = DDC_ADDR,
> - .flags = I2C_M_RD,
> - .len= len,
> - .buf= buf,
> + switch (segment) {
> + /* To reduce traffic on I2C, we request the i2c xfer
> + * for segment addr only if 4 block edid data is
> + * present.
> + * 0 : DDC
> + * 1 : E-DDC
> + */
This comment is a bit misleading: We don't avoid the segment xfer to
reduce i2c traffic, but to avoid upsetting any non-compliant screens.
> + case 0:
> + do {
Keeping the loop as the outermost would imo be clearer and avoid
duplicating it (it also would make the patch a bit smaller). You could
even do a trick with the msgs array like this:
msgs[] = { full i2c xfer including segment addr}
xfers = 3;
/* Avoid sending the segment addr to not upset non-compliant ddc
* monitors. */
if (!segments)
msgs++, len--;
i2c_transefer(adapter, msgs, len);
Also, I think it'd be good to set the IGNORE_NAK on the start addre
transfer, too (but in a separate patch). At least I think we've seen
screens out there that need this :(
Yours, Daniel
> + struct i2c_msg msgs[] = {
> + {
> + .addr = DDC_ADDR,
> + .flags = 0,
> + .len= 1,
> + .buf= &start,
> + }, {
> + .addr = DDC_ADDR,
> + .flags = I2C_M_RD,
> + .len= len,
> + .buf= buf,
> + }
> + };
> + ret = i2c_transfer(adapter, msgs, 2);
> + if (ret == -ENXIO) {
> + DRM_DEBUG_KMS("drm: skipping non-existent
> adapter %s\n",
> + adapter->name);
> + break;
> }
> - };
> - ret = i2c_transfer(adapter, msgs, 2);
> - if (ret == -ENXIO) {
> - DRM_DEBUG_KMS("drm: skipping non-existent adapter %s\n",
> - adapter->name);
> - break;
> - }
> - } while (ret != 2 && --retries);
> + } while (ret != 2 && --retries);
> +
> + return ret == 2 ? 0 : -1;
> + case 1:
> + do {
> + struct i2c_msg msgs[] = {
> + { /*set segment pointer */
> + .addr = DDC_SEGMENT_ADDR,
> + .flags = segFlags,
> + .len= 1,
> + .buf= &segment,
> + }, { /*set offset */
> + .addr = DDC_ADDR,
> +
Re: [PATCH V3] drm: edid: add support for E-DDC
Thanks for the comments, will upload patch set
with your comments.
On Fri, Aug 24, 2012 at 11:20 AM, Daniel Vetter wrote:
> On Fri, Aug 24, 2012 at 02:56:50PM +0530, Shirish S wrote:
> > The current logic for probing ddc is limited to
> > 2 blocks (256 bytes), this patch adds support
> > for the 4 block (512) data.
> >
> > To do this, a single 8-bit segment index is
> > passed to the display via the I2C address 30h.
> > Data from the selected segment is then immediately
> > read via the regular DDC2 address using a repeated
> > I2C 'START' signal.
> >
> > Signed-off-by: Shirish S
> > ---
> > drivers/gpu/drm/drm_edid.c | 83
> ---
> > 1 files changed, 62 insertions(+), 21 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> > index a8743c3..a10a130 100644
> > --- a/drivers/gpu/drm/drm_edid.c
> > +++ b/drivers/gpu/drm/drm_edid.c
> > @@ -254,6 +254,8 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter,
> unsigned char *buf,
> > int block, int len)
> > {
> > unsigned char start = block * EDID_LENGTH;
> > + unsigned char segment = block >> 1;
> > + unsigned short segFlags = segment ? 0 : I2C_M_IGNORE_NAK;
>
> You can inline segFlags to the only place it's used.
>
> > int ret, retries = 5;
> >
> > /* The core i2c driver will automatically retry the transfer if the
> > @@ -262,29 +264,68 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter,
> unsigned char *buf,
> >* generate spurious NAKs and timeouts. Retrying the transfer
> >* of the individual block a few times seems to overcome this.
> >*/
> > - do {
> > - struct i2c_msg msgs[] = {
> > - {
> > - .addr = DDC_ADDR,
> > - .flags = 0,
> > - .len= 1,
> > - .buf= &start,
> > - }, {
> > - .addr = DDC_ADDR,
> > - .flags = I2C_M_RD,
> > - .len= len,
> > - .buf= buf,
> > + switch (segment) {
> > + /* To reduce traffic on I2C, we request the i2c xfer
> > + * for segment addr only if 4 block edid data is
> > + * present.
> > + * 0 : DDC
> > + * 1 : E-DDC
> > + */
>
> This comment is a bit misleading: We don't avoid the segment xfer to
> reduce i2c traffic, but to avoid upsetting any non-compliant screens.
>
> > + case 0:
> > + do {
>
> Keeping the loop as the outermost would imo be clearer and avoid
> duplicating it (it also would make the patch a bit smaller). You could
> even do a trick with the msgs array like this:
>
> msgs[] = { full i2c xfer including segment addr}
> xfers = 3;
>
> /* Avoid sending the segment addr to not upset non-compliant ddc
> * monitors. */
> if (!segments)
> msgs++, len--;
>
> i2c_transefer(adapter, msgs, len);
>
> Also, I think it'd be good to set the IGNORE_NAK on the start addre
> transfer, too (but in a separate patch). At least I think we've seen
> screens out there that need this :(
>
> Yours, Daniel
>
> > + struct i2c_msg msgs[] = {
> > + {
> > + .addr = DDC_ADDR,
> > + .flags = 0,
> > + .len= 1,
> > + .buf= &start,
> > + }, {
> > + .addr = DDC_ADDR,
> > + .flags = I2C_M_RD,
> > + .len= len,
> > + .buf= buf,
> > + }
> > + };
> > + ret = i2c_transfer(adapter, msgs, 2);
> > + if (ret == -ENXIO) {
> > + DRM_DEBUG_KMS("drm: skipping non-existent
> adapter %s\n",
> > + adapter->name);
> > + break;
> > }
> > - };
> > - ret = i2c_transfer(adapter, msgs, 2);
> > - if (ret == -ENXIO) {
> > - DRM_DEBUG_KMS("drm: skipping non-existent adapter
> %s\n",
> > - adapter->name);
> > - break;
> > - }
> > - } while (ret != 2 && --retries);
> > + } while (ret != 2 && --retries);
> > +
> > + return ret == 2 ? 0 : -1;
> > + case 1:
> > + do {
> > + struct i2c_msg msgs[] = {
> > + { /*set segment pointer */
> > +
[PATCH V3] drm: edid: add support for E-DDC
Thanks for the comments, will upload patch set
with your comments.
On Fri, Aug 24, 2012 at 11:20 AM, Daniel Vetter wrote:
> On Fri, Aug 24, 2012 at 02:56:50PM +0530, Shirish S wrote:
> > The current logic for probing ddc is limited to
> > 2 blocks (256 bytes), this patch adds support
> > for the 4 block (512) data.
> >
> > To do this, a single 8-bit segment index is
> > passed to the display via the I2C address 30h.
> > Data from the selected segment is then immediately
> > read via the regular DDC2 address using a repeated
> > I2C 'START' signal.
> >
> > Signed-off-by: Shirish S
> > ---
> > drivers/gpu/drm/drm_edid.c | 83
> ---
> > 1 files changed, 62 insertions(+), 21 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> > index a8743c3..a10a130 100644
> > --- a/drivers/gpu/drm/drm_edid.c
> > +++ b/drivers/gpu/drm/drm_edid.c
> > @@ -254,6 +254,8 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter,
> unsigned char *buf,
> > int block, int len)
> > {
> > unsigned char start = block * EDID_LENGTH;
> > + unsigned char segment = block >> 1;
> > + unsigned short segFlags = segment ? 0 : I2C_M_IGNORE_NAK;
>
> You can inline segFlags to the only place it's used.
>
> > int ret, retries = 5;
> >
> > /* The core i2c driver will automatically retry the transfer if the
> > @@ -262,29 +264,68 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter,
> unsigned char *buf,
> >* generate spurious NAKs and timeouts. Retrying the transfer
> >* of the individual block a few times seems to overcome this.
> >*/
> > - do {
> > - struct i2c_msg msgs[] = {
> > - {
> > - .addr = DDC_ADDR,
> > - .flags = 0,
> > - .len= 1,
> > - .buf= &start,
> > - }, {
> > - .addr = DDC_ADDR,
> > - .flags = I2C_M_RD,
> > - .len= len,
> > - .buf= buf,
> > + switch (segment) {
> > + /* To reduce traffic on I2C, we request the i2c xfer
> > + * for segment addr only if 4 block edid data is
> > + * present.
> > + * 0 : DDC
> > + * 1 : E-DDC
> > + */
>
> This comment is a bit misleading: We don't avoid the segment xfer to
> reduce i2c traffic, but to avoid upsetting any non-compliant screens.
>
> > + case 0:
> > + do {
>
> Keeping the loop as the outermost would imo be clearer and avoid
> duplicating it (it also would make the patch a bit smaller). You could
> even do a trick with the msgs array like this:
>
> msgs[] = { full i2c xfer including segment addr}
> xfers = 3;
>
> /* Avoid sending the segment addr to not upset non-compliant ddc
> * monitors. */
> if (!segments)
> msgs++, len--;
>
> i2c_transefer(adapter, msgs, len);
>
> Also, I think it'd be good to set the IGNORE_NAK on the start addre
> transfer, too (but in a separate patch). At least I think we've seen
> screens out there that need this :(
>
> Yours, Daniel
>
> > + struct i2c_msg msgs[] = {
> > + {
> > + .addr = DDC_ADDR,
> > + .flags = 0,
> > + .len= 1,
> > + .buf= &start,
> > + }, {
> > + .addr = DDC_ADDR,
> > + .flags = I2C_M_RD,
> > + .len= len,
> > + .buf= buf,
> > + }
> > + };
> > + ret = i2c_transfer(adapter, msgs, 2);
> > + if (ret == -ENXIO) {
> > + DRM_DEBUG_KMS("drm: skipping non-existent
> adapter %s\n",
> > + adapter->name);
> > + break;
> > }
> > - };
> > - ret = i2c_transfer(adapter, msgs, 2);
> > - if (ret == -ENXIO) {
> > - DRM_DEBUG_KMS("drm: skipping non-existent adapter
> %s\n",
> > - adapter->name);
> > - break;
> > - }
> > - } while (ret != 2 && --retries);
> > + } while (ret != 2 && --retries);
> > +
> > + return ret == 2 ? 0 : -1;
> > + case 1:
> > + do {
> > + struct i2c_msg msgs[] = {
> > + { /*set segment pointer */
> > +
[PATCH V3] drm: edid: add support for E-DDC
The current logic for probing ddc is limited to
2 blocks (256 bytes), this patch adds support
for the 4 block (512) data.
To do this, a single 8-bit segment index is
passed to the display via the I2C address 30h.
Data from the selected segment is then immediately
read via the regular DDC2 address using a repeated
I2C 'START' signal.
Signed-off-by: Shirish S
---
drivers/gpu/drm/drm_edid.c | 83 ---
1 files changed, 62 insertions(+), 21 deletions(-)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index a8743c3..a10a130 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -254,6 +254,8 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned
char *buf,
int block, int len)
{
unsigned char start = block * EDID_LENGTH;
+ unsigned char segment = block >> 1;
+ unsigned short segFlags = segment ? 0 : I2C_M_IGNORE_NAK;
int ret, retries = 5;
/* The core i2c driver will automatically retry the transfer if the
@@ -262,29 +264,68 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter,
unsigned char *buf,
* generate spurious NAKs and timeouts. Retrying the transfer
* of the individual block a few times seems to overcome this.
*/
- do {
- struct i2c_msg msgs[] = {
- {
- .addr = DDC_ADDR,
- .flags = 0,
- .len= 1,
- .buf= &start,
- }, {
- .addr = DDC_ADDR,
- .flags = I2C_M_RD,
- .len= len,
- .buf= buf,
+ switch (segment) {
+ /* To reduce traffic on I2C, we request the i2c xfer
+* for segment addr only if 4 block edid data is
+* present.
+* 0 : DDC
+* 1 : E-DDC
+*/
+ case 0:
+ do {
+ struct i2c_msg msgs[] = {
+ {
+ .addr = DDC_ADDR,
+ .flags = 0,
+ .len= 1,
+ .buf= &start,
+ }, {
+ .addr = DDC_ADDR,
+ .flags = I2C_M_RD,
+ .len= len,
+ .buf= buf,
+ }
+ };
+ ret = i2c_transfer(adapter, msgs, 2);
+ if (ret == -ENXIO) {
+ DRM_DEBUG_KMS("drm: skipping non-existent
adapter %s\n",
+ adapter->name);
+ break;
}
- };
- ret = i2c_transfer(adapter, msgs, 2);
- if (ret == -ENXIO) {
- DRM_DEBUG_KMS("drm: skipping non-existent adapter %s\n",
- adapter->name);
- break;
- }
- } while (ret != 2 && --retries);
+ } while (ret != 2 && --retries);
+
+ return ret == 2 ? 0 : -1;
+ case 1:
+ do {
+ struct i2c_msg msgs[] = {
+ { /*set segment pointer */
+ .addr = DDC_SEGMENT_ADDR,
+ .flags = segFlags,
+ .len= 1,
+ .buf= &segment,
+ }, { /*set offset */
+ .addr = DDC_ADDR,
+ .flags = 0,
+ .len= 1,
+ .buf= &start,
+ }, { /*set data */
+ .addr = DDC_ADDR,
+ .flags = I2C_M_RD,
+ .len= len,
+ .buf= buf,
+ }
+ };
+ ret = i2c_transfer(adapter, msgs, 3);
+ if (ret == -ENXIO) {
+ DRM_DEBUG_KMS("drm: skipping non-existent
adapter %s\n",
+ adapter->name);
+ break;
+ }
+ } while (ret != 3 && --retries);
- return ret == 2 ? 0 : -1;
+ return ret == 3 ? 0 : -1;
+ }
+
[PATCH V3] drm: edid: add support for E-DDC
This patch adds support in probing 4 block edid data, for E-DDC. This is the first test case in CTS, for HDMI compliance. Changes from V2: Add switch for DDC and E-DDC Based on drm-next branch Shirish S (1): drm: edid: add support for E-DDC drivers/gpu/drm/drm_edid.c | 87 1 files changed, 64 insertions(+), 23 deletions(-)
Re: [PATCH V3] drm: edid: add support for E-DDC
On Fri, Aug 24, 2012 at 02:56:50PM +0530, Shirish S wrote:
> The current logic for probing ddc is limited to
> 2 blocks (256 bytes), this patch adds support
> for the 4 block (512) data.
>
> To do this, a single 8-bit segment index is
> passed to the display via the I2C address 30h.
> Data from the selected segment is then immediately
> read via the regular DDC2 address using a repeated
> I2C 'START' signal.
>
> Signed-off-by: Shirish S
> ---
> drivers/gpu/drm/drm_edid.c | 83 ---
> 1 files changed, 62 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index a8743c3..a10a130 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -254,6 +254,8 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter,
> unsigned char *buf,
> int block, int len)
> {
> unsigned char start = block * EDID_LENGTH;
> + unsigned char segment = block >> 1;
> + unsigned short segFlags = segment ? 0 : I2C_M_IGNORE_NAK;
You can inline segFlags to the only place it's used.
> int ret, retries = 5;
>
> /* The core i2c driver will automatically retry the transfer if the
> @@ -262,29 +264,68 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter,
> unsigned char *buf,
>* generate spurious NAKs and timeouts. Retrying the transfer
>* of the individual block a few times seems to overcome this.
>*/
> - do {
> - struct i2c_msg msgs[] = {
> - {
> - .addr = DDC_ADDR,
> - .flags = 0,
> - .len= 1,
> - .buf= &start,
> - }, {
> - .addr = DDC_ADDR,
> - .flags = I2C_M_RD,
> - .len= len,
> - .buf= buf,
> + switch (segment) {
> + /* To reduce traffic on I2C, we request the i2c xfer
> + * for segment addr only if 4 block edid data is
> + * present.
> + * 0 : DDC
> + * 1 : E-DDC
> + */
This comment is a bit misleading: We don't avoid the segment xfer to
reduce i2c traffic, but to avoid upsetting any non-compliant screens.
> + case 0:
> + do {
Keeping the loop as the outermost would imo be clearer and avoid
duplicating it (it also would make the patch a bit smaller). You could
even do a trick with the msgs array like this:
msgs[] = { full i2c xfer including segment addr}
xfers = 3;
/* Avoid sending the segment addr to not upset non-compliant ddc
* monitors. */
if (!segments)
msgs++, len--;
i2c_transefer(adapter, msgs, len);
Also, I think it'd be good to set the IGNORE_NAK on the start addre
transfer, too (but in a separate patch). At least I think we've seen
screens out there that need this :(
Yours, Daniel
> + struct i2c_msg msgs[] = {
> + {
> + .addr = DDC_ADDR,
> + .flags = 0,
> + .len= 1,
> + .buf= &start,
> + }, {
> + .addr = DDC_ADDR,
> + .flags = I2C_M_RD,
> + .len= len,
> + .buf= buf,
> + }
> + };
> + ret = i2c_transfer(adapter, msgs, 2);
> + if (ret == -ENXIO) {
> + DRM_DEBUG_KMS("drm: skipping non-existent
> adapter %s\n",
> + adapter->name);
> + break;
> }
> - };
> - ret = i2c_transfer(adapter, msgs, 2);
> - if (ret == -ENXIO) {
> - DRM_DEBUG_KMS("drm: skipping non-existent adapter %s\n",
> - adapter->name);
> - break;
> - }
> - } while (ret != 2 && --retries);
> + } while (ret != 2 && --retries);
> +
> + return ret == 2 ? 0 : -1;
> + case 1:
> + do {
> + struct i2c_msg msgs[] = {
> + { /*set segment pointer */
> + .addr = DDC_SEGMENT_ADDR,
> + .flags = segFlags,
> + .len= 1,
> + .buf= &segment,
> + }, { /*set offset */
> + .addr = DDC_ADDR,
> +
[PATCH V3] drm: edid: add support for E-DDC
The current logic for probing ddc is limited to
2 blocks (256 bytes), this patch adds support
for the 4 block (512) data.
To do this, a single 8-bit segment index is
passed to the display via the I2C address 30h.
Data from the selected segment is then immediately
read via the regular DDC2 address using a repeated
I2C 'START' signal.
Signed-off-by: Shirish S
---
drivers/gpu/drm/drm_edid.c | 83 ---
1 files changed, 62 insertions(+), 21 deletions(-)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index a8743c3..a10a130 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -254,6 +254,8 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned
char *buf,
int block, int len)
{
unsigned char start = block * EDID_LENGTH;
+ unsigned char segment = block >> 1;
+ unsigned short segFlags = segment ? 0 : I2C_M_IGNORE_NAK;
int ret, retries = 5;
/* The core i2c driver will automatically retry the transfer if the
@@ -262,29 +264,68 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter,
unsigned char *buf,
* generate spurious NAKs and timeouts. Retrying the transfer
* of the individual block a few times seems to overcome this.
*/
- do {
- struct i2c_msg msgs[] = {
- {
- .addr = DDC_ADDR,
- .flags = 0,
- .len= 1,
- .buf= &start,
- }, {
- .addr = DDC_ADDR,
- .flags = I2C_M_RD,
- .len= len,
- .buf= buf,
+ switch (segment) {
+ /* To reduce traffic on I2C, we request the i2c xfer
+* for segment addr only if 4 block edid data is
+* present.
+* 0 : DDC
+* 1 : E-DDC
+*/
+ case 0:
+ do {
+ struct i2c_msg msgs[] = {
+ {
+ .addr = DDC_ADDR,
+ .flags = 0,
+ .len= 1,
+ .buf= &start,
+ }, {
+ .addr = DDC_ADDR,
+ .flags = I2C_M_RD,
+ .len= len,
+ .buf= buf,
+ }
+ };
+ ret = i2c_transfer(adapter, msgs, 2);
+ if (ret == -ENXIO) {
+ DRM_DEBUG_KMS("drm: skipping non-existent
adapter %s\n",
+ adapter->name);
+ break;
}
- };
- ret = i2c_transfer(adapter, msgs, 2);
- if (ret == -ENXIO) {
- DRM_DEBUG_KMS("drm: skipping non-existent adapter %s\n",
- adapter->name);
- break;
- }
- } while (ret != 2 && --retries);
+ } while (ret != 2 && --retries);
+
+ return ret == 2 ? 0 : -1;
+ case 1:
+ do {
+ struct i2c_msg msgs[] = {
+ { /*set segment pointer */
+ .addr = DDC_SEGMENT_ADDR,
+ .flags = segFlags,
+ .len= 1,
+ .buf= &segment,
+ }, { /*set offset */
+ .addr = DDC_ADDR,
+ .flags = 0,
+ .len= 1,
+ .buf= &start,
+ }, { /*set data */
+ .addr = DDC_ADDR,
+ .flags = I2C_M_RD,
+ .len= len,
+ .buf= buf,
+ }
+ };
+ ret = i2c_transfer(adapter, msgs, 3);
+ if (ret == -ENXIO) {
+ DRM_DEBUG_KMS("drm: skipping non-existent
adapter %s\n",
+ adapter->name);
+ break;
+ }
+ } while (ret != 3 && --retries);
- return ret == 2 ? 0 : -1;
+ return ret == 3 ? 0 : -1;
+ }
+
[PATCH V3] drm: edid: add support for E-DDC
This patch adds support in probing 4 block edid data, for E-DDC. This is the first test case in CTS, for HDMI compliance. Changes from V2: Add switch for DDC and E-DDC Based on drm-next branch Shirish S (1): drm: edid: add support for E-DDC drivers/gpu/drm/drm_edid.c | 87 1 files changed, 64 insertions(+), 23 deletions(-) ___ dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel
