| Message ID | 1346251588-17104-2-git-send-email-s.shirish@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Aug 29, 2012 at 4:46 PM, Shirish S <s.shirish@samsung.com> 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 <s.shirish@samsung.com> If you resend patches it'd be nice to keep a changelog of the patch itself somewhere, otherwise it's just more work to figure that out for reviewers. Also, you can usually attach reviewed-by tags (like mine) to a patch resend if you don't change the patch massively ... -Daniel > --- > drivers/gpu/drm/drm_edid.c | 22 +++++++++++++++++++--- > 1 files changed, 19 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c > index bcc4725..b9ffc30 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 char xfers = segment ? 3 : 2; > int ret, retries = 5; > > /* The core i2c driver will automatically retry the transfer if the > @@ -265,6 +267,11 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf, > do { > struct i2c_msg msgs[] = { > { > + .addr = DDC_SEGMENT_ADDR, > + .flags = segment ? 0 : I2C_M_IGNORE_NAK, > + .len = 1, > + .buf = &segment, > + }, { > .addr = DDC_ADDR, > .flags = 0, > .len = 1, > @@ -276,15 +283,24 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf, > .buf = buf, > } > }; > - ret = i2c_transfer(adapter, msgs, 2); > + > + /* > + * Avoid sending the segment addr to not upset non-compliant ddc > + * monitors. > + */ > + if (!segment) > + ret = i2c_transfer(adapter, &msgs[1], xfers); > + else > + ret = i2c_transfer(adapter, msgs, xfers); > + > if (ret == -ENXIO) { > DRM_DEBUG_KMS("drm: skipping non-existent adapter %s\n", > adapter->name); > break; > } > - } while (ret != 2 && --retries); > + } while (ret != xfers && --retries); > > - return ret == 2 ? 0 : -1; > + return ret == xfers ? 0 : -1; > } > > static bool drm_edid_is_zero(u8 *in_edid, int length) > -- > 1.7.0.4 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/dri-devel
Thanks for the comments Daniel and Jean I will upload patch set 6. This shall include Jean's review coments. And i will tag Daniel,Jean and Ville as reviewed. Regards, Shirish S On Wed, Aug 29, 2012 at 9:12 AM, Daniel Vetter <daniel@ffwll.ch> wrote: > On Wed, Aug 29, 2012 at 4:46 PM, Shirish S <s.shirish@samsung.com> 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 <s.shirish@samsung.com> > > If you resend patches it'd be nice to keep a changelog of the patch > itself somewhere, otherwise it's just more work to figure that out for > reviewers. Also, you can usually attach reviewed-by tags (like mine) > to a patch resend if you don't change the patch massively ... > -Daniel > > > --- > > drivers/gpu/drm/drm_edid.c | 22 +++++++++++++++++++--- > > 1 files changed, 19 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c > > index bcc4725..b9ffc30 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 char xfers = segment ? 3 : 2; > > int ret, retries = 5; > > > > /* The core i2c driver will automatically retry the transfer if > the > > @@ -265,6 +267,11 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter, > unsigned char *buf, > > do { > > struct i2c_msg msgs[] = { > > { > > + .addr = DDC_SEGMENT_ADDR, > > + .flags = segment ? 0 : I2C_M_IGNORE_NAK, > > + .len = 1, > > + .buf = &segment, > > + }, { > > .addr = DDC_ADDR, > > .flags = 0, > > .len = 1, > > @@ -276,15 +283,24 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter, > unsigned char *buf, > > .buf = buf, > > } > > }; > > - ret = i2c_transfer(adapter, msgs, 2); > > + > > + /* > > + * Avoid sending the segment addr to not upset non-compliant ddc > > + * monitors. > > + */ > > + if (!segment) > > + ret = i2c_transfer(adapter, &msgs[1], xfers); > > + else > > + ret = i2c_transfer(adapter, msgs, xfers); > > + > > if (ret == -ENXIO) { > > DRM_DEBUG_KMS("drm: skipping non-existent > adapter %s\n", > > adapter->name); > > break; > > } > > - } while (ret != 2 && --retries); > > + } while (ret != xfers && --retries); > > > > - return ret == 2 ? 0 : -1; > > + return ret == xfers ? 0 : -1; > > } > > > > static bool drm_edid_is_zero(u8 *in_edid, int length) > > -- > > 1.7.0.4 > > > > _______________________________________________ > > dri-devel mailing list > > dri-devel@lists.freedesktop.org > > http://lists.freedesktop.org/mailman/listinfo/dri-devel > > > > -- > Daniel Vetter > daniel.vetter@ffwll.ch - +41 (0) 79 364 57 48 - http://blog.ffwll.ch > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/dri-devel >
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index bcc4725..b9ffc30 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 char xfers = segment ? 3 : 2; int ret, retries = 5; /* The core i2c driver will automatically retry the transfer if the @@ -265,6 +267,11 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf, do { struct i2c_msg msgs[] = { { + .addr = DDC_SEGMENT_ADDR, + .flags = segment ? 0 : I2C_M_IGNORE_NAK, + .len = 1, + .buf = &segment, + }, { .addr = DDC_ADDR, .flags = 0, .len = 1, @@ -276,15 +283,24 @@ drm_do_probe_ddc_edid(struct i2c_adapter *adapter, unsigned char *buf, .buf = buf, } }; - ret = i2c_transfer(adapter, msgs, 2); + + /* + * Avoid sending the segment addr to not upset non-compliant ddc + * monitors. + */ + if (!segment) + ret = i2c_transfer(adapter, &msgs[1], xfers); + else + ret = i2c_transfer(adapter, msgs, xfers); + if (ret == -ENXIO) { DRM_DEBUG_KMS("drm: skipping non-existent adapter %s\n", adapter->name); break; } - } while (ret != 2 && --retries); + } while (ret != xfers && --retries); - return ret == 2 ? 0 : -1; + return ret == xfers ? 0 : -1; } static bool drm_edid_is_zero(u8 *in_edid, int length)
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 <s.shirish@samsung.com> --- drivers/gpu/drm/drm_edid.c | 22 +++++++++++++++++++--- 1 files changed, 19 insertions(+), 3 deletions(-)