| Message ID | 1435314429-10511-2-git-send-email-l.stach@pengutronix.de (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
On Fri, Jun 26, 2015 at 12:27:09PM +0200, Lucas Stach wrote: > From: Philipp Zabel <p.zabel@pengutronix.de> > > According to the data sheet, the minimum horizontal blanking interval > is 54 clocks (1 + 52 + 1), but tests with a Nitrogen6X have shown the > minimum working horizontal blanking interval to be 60 clocks. > > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> > Signed-off-by: Lucas Stach <l.stach@pengutronix.de> > --- > drivers/gpu/drm/panel/panel-simple.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c > index dc6a923c89d7..7196b940a928 100644 > --- a/drivers/gpu/drm/panel/panel-simple.c > +++ b/drivers/gpu/drm/panel/panel-simple.c > @@ -713,7 +713,12 @@ static const struct display_timing hannstar_hsd070pww1_timing = { > .hactive = { 1280, 1280, 1280 }, > .hfront_porch = { 1, 1, 10 }, > .hback_porch = { 1, 1, 10 }, > - .hsync_len = { 52, 158, 661 }, > + /* > + * According to the data sheet, the minimum horizontal blanking interval > + * is 54 clocks (1 + 52 + 1), but tests with a Nitrogen6X have shown the > + * minimum working horizontal blanking interval to be 60 clocks. > + */ > + .hsync_len = { 58, 158, 661 }, 58 != 60, so which one is the truth here? Thierry
Am Freitag, den 07.08.2015, 14:43 +0200 schrieb Thierry Reding: > On Fri, Jun 26, 2015 at 12:27:09PM +0200, Lucas Stach wrote: > > From: Philipp Zabel <p.zabel@pengutronix.de> > > > > According to the data sheet, the minimum horizontal blanking interval > > is 54 clocks (1 + 52 + 1), but tests with a Nitrogen6X have shown the > > minimum working horizontal blanking interval to be 60 clocks. > > > > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> > > Signed-off-by: Lucas Stach <l.stach@pengutronix.de> > > --- > > drivers/gpu/drm/panel/panel-simple.c | 7 ++++++- > > 1 file changed, 6 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c > > index dc6a923c89d7..7196b940a928 100644 > > --- a/drivers/gpu/drm/panel/panel-simple.c > > +++ b/drivers/gpu/drm/panel/panel-simple.c > > @@ -713,7 +713,12 @@ static const struct display_timing hannstar_hsd070pww1_timing = { > > .hactive = { 1280, 1280, 1280 }, > > .hfront_porch = { 1, 1, 10 }, > > .hback_porch = { 1, 1, 10 }, > > - .hsync_len = { 52, 158, 661 }, > > + /* > > + * According to the data sheet, the minimum horizontal blanking interval > > + * is 54 clocks (1 + 52 + 1), but tests with a Nitrogen6X have shown the > > + * minimum working horizontal blanking interval to be 60 clocks. > > + */ > > + .hsync_len = { 58, 158, 661 }, > > 58 != 60, so which one is the truth here? > The comment says blanking interval must be at least 60 clocks. Blanking interval = front_porch + hsync_len + back_porch. Both minimum front and back porch for this panel are 1 clock, so the values match the comment. Regards, Lucas
diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c index dc6a923c89d7..7196b940a928 100644 --- a/drivers/gpu/drm/panel/panel-simple.c +++ b/drivers/gpu/drm/panel/panel-simple.c @@ -713,7 +713,12 @@ static const struct display_timing hannstar_hsd070pww1_timing = { .hactive = { 1280, 1280, 1280 }, .hfront_porch = { 1, 1, 10 }, .hback_porch = { 1, 1, 10 }, - .hsync_len = { 52, 158, 661 }, + /* + * According to the data sheet, the minimum horizontal blanking interval + * is 54 clocks (1 + 52 + 1), but tests with a Nitrogen6X have shown the + * minimum working horizontal blanking interval to be 60 clocks. + */ + .hsync_len = { 58, 158, 661 }, .vactive = { 800, 800, 800 }, .vfront_porch = { 1, 1, 10 }, .vback_porch = { 1, 1, 10 },