[PATCH] Revert "drm/i915/dp: Use auxch precharge value of 5 everywhere"
On Thu, Jun 14, 2012 at 10:15:00PM +0200, Daniel Vetter wrote: > This reverts commit 092945e11c5b84f66dd08f0b87fb729715d377bc. > > This commit prevents a DP screen from properly training the link. > Oddly enough it works, once the machine has been warm-booted with an > older kernel. > > According to DP docs this _should_ have been the right precharge time. > Also, the commit that originally introduces this was just general snb > DP enabling and didn't mention any specific reason for this special > value. Whatever, trust the reporter that this makes things worse and > let's just revert it. > > v2: Less spelling fail. > > Cc: Adam Jackson > Cc: Jesse Barnes > Reported-by: "Wouter M. Koolen" > Buglink: https://lkml.org/lkml/2012/6/14/301 > Signed-Off-by: Daniel Vetter No one yelled around with a better idea, so I've picked this up for fixes with cc stable. -Daniel -- Daniel Vetter Mail: daniel at ffwll.ch Mobile: +41 (0)79 365 57 48
Re: [PATCH] Revert "drm/i915/dp: Use auxch precharge value of 5 everywhere"
On Thu, Jun 14, 2012 at 10:15:00PM +0200, Daniel Vetter wrote: > This reverts commit 092945e11c5b84f66dd08f0b87fb729715d377bc. > > This commit prevents a DP screen from properly training the link. > Oddly enough it works, once the machine has been warm-booted with an > older kernel. > > According to DP docs this _should_ have been the right precharge time. > Also, the commit that originally introduces this was just general snb > DP enabling and didn't mention any specific reason for this special > value. Whatever, trust the reporter that this makes things worse and > let's just revert it. > > v2: Less spelling fail. > > Cc: Adam Jackson > Cc: Jesse Barnes > Reported-by: "Wouter M. Koolen" > Buglink: https://lkml.org/lkml/2012/6/14/301 > Signed-Off-by: Daniel Vetter No one yelled around with a better idea, so I've picked this up for fixes with cc stable. -Daniel -- Daniel Vetter Mail: dan...@ffwll.ch Mobile: +41 (0)79 365 57 48 ___ dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel
[PATCH] Revert "drm/i915/dp: Use auxch precharge value of 5 everywhere"
This reverts commit 092945e11c5b84f66dd08f0b87fb729715d377bc. This commit prevents a DP screen from properly training the link. Oddly enough it works, once the machine has been warm-booted with an older kernel. According to DP docs this _should_ have been the right precharge time. Also, the commit that originally introduces this was just general snb DP enabling and didn't mention any specific reason for this special value. Whatever, trust the reporter that this makes things worse and let's just revert it. v2: Less spelling fail. Cc: Adam Jackson Cc: Jesse Barnes Reported-by: "Wouter M. Koolen" Buglink: https://lkml.org/lkml/2012/6/14/301 Signed-Off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_dp.c |7 ++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index c574ff0..a4b3887 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -371,7 +371,7 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, int recv_bytes; uint32_t status; uint32_t aux_clock_divider; - int try, precharge = 5; + int try, precharge; intel_dp_check_edp(intel_dp); /* The clock divider is based off the hrawclk, @@ -391,6 +391,11 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, else aux_clock_divider = intel_hrawclk(dev) / 2; + if (IS_GEN6(dev)) + precharge = 3; + else + precharge = 5; + /* Try to wait for any previous AUX channel activity */ for (try = 0; try < 3; try++) { status = I915_READ(ch_ctl); -- 1.7.10
[PATCH] Revert "drm/i915/dp: Use auxch precharge value of 5 everywhere"
This reverts commit 092945e11c5b84f66dd08f0b87fb729715d377bc. This commit prevents a DP screen from properly training the link. Oddly enough it works, once the machine has been warm-boot with an older kernel. According to DP docs this _should_ have been the right precharge time. Also, the commit that originally introduce this was just general snb DP enabling and didn't mention any specific reason for this special value. Whatever, trust the reporter that this makes things worse. Cc: Adam Jackson Cc: Jesse Barnes Reported-by: "Wouter M. Koolen" Buglink: https://lkml.org/lkml/2012/6/14/301 Signed-Off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_dp.c |7 ++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index c574ff0..a4b3887 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -371,7 +371,7 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, int recv_bytes; uint32_t status; uint32_t aux_clock_divider; - int try, precharge = 5; + int try, precharge; intel_dp_check_edp(intel_dp); /* The clock divider is based off the hrawclk, @@ -391,6 +391,11 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, else aux_clock_divider = intel_hrawclk(dev) / 2; + if (IS_GEN6(dev)) + precharge = 3; + else + precharge = 5; + /* Try to wait for any previous AUX channel activity */ for (try = 0; try < 3; try++) { status = I915_READ(ch_ctl); -- 1.7.10
[PATCH] Revert "drm/i915/dp: Use auxch precharge value of 5 everywhere"
This reverts commit 092945e11c5b84f66dd08f0b87fb729715d377bc. This commit prevents a DP screen from properly training the link. Oddly enough it works, once the machine has been warm-booted with an older kernel. According to DP docs this _should_ have been the right precharge time. Also, the commit that originally introduces this was just general snb DP enabling and didn't mention any specific reason for this special value. Whatever, trust the reporter that this makes things worse and let's just revert it. v2: Less spelling fail. Cc: Adam Jackson Cc: Jesse Barnes Reported-by: "Wouter M. Koolen" Buglink: https://lkml.org/lkml/2012/6/14/301 Signed-Off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_dp.c |7 ++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index c574ff0..a4b3887 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -371,7 +371,7 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, int recv_bytes; uint32_t status; uint32_t aux_clock_divider; - int try, precharge = 5; + int try, precharge; intel_dp_check_edp(intel_dp); /* The clock divider is based off the hrawclk, @@ -391,6 +391,11 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, else aux_clock_divider = intel_hrawclk(dev) / 2; + if (IS_GEN6(dev)) + precharge = 3; + else + precharge = 5; + /* Try to wait for any previous AUX channel activity */ for (try = 0; try < 3; try++) { status = I915_READ(ch_ctl); -- 1.7.10 ___ dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel
[PATCH] Revert "drm/i915/dp: Use auxch precharge value of 5 everywhere"
This reverts commit 092945e11c5b84f66dd08f0b87fb729715d377bc. This commit prevents a DP screen from properly training the link. Oddly enough it works, once the machine has been warm-boot with an older kernel. According to DP docs this _should_ have been the right precharge time. Also, the commit that originally introduce this was just general snb DP enabling and didn't mention any specific reason for this special value. Whatever, trust the reporter that this makes things worse. Cc: Adam Jackson Cc: Jesse Barnes Reported-by: "Wouter M. Koolen" Buglink: https://lkml.org/lkml/2012/6/14/301 Signed-Off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_dp.c |7 ++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index c574ff0..a4b3887 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -371,7 +371,7 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, int recv_bytes; uint32_t status; uint32_t aux_clock_divider; - int try, precharge = 5; + int try, precharge; intel_dp_check_edp(intel_dp); /* The clock divider is based off the hrawclk, @@ -391,6 +391,11 @@ intel_dp_aux_ch(struct intel_dp *intel_dp, else aux_clock_divider = intel_hrawclk(dev) / 2; + if (IS_GEN6(dev)) + precharge = 3; + else + precharge = 5; + /* Try to wait for any previous AUX channel activity */ for (try = 0; try < 3; try++) { status = I915_READ(ch_ctl); -- 1.7.10 ___ dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel