diff mbox

[v4,RESEND,1/5] drm/dp_helper: Increase retry interval to 1000us

Message ID 1459175606-13875-2-git-send-email-cpaul@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

cpaul@redhat.com March 28, 2016, 2:33 p.m. UTC
This is part of a patch series to migrate all of the workarounds for
commonly seen behavior from bad sinks in intel_dp_dpcd_read_wake() to
drm's DP helper.

Signed-off-by: Lyude <cpaul@redhat.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Daniel Vetter March 29, 2016, 8:27 a.m. UTC | #1
On Mon, Mar 28, 2016 at 10:33:22AM -0400, Lyude wrote:
> This is part of a patch series to migrate all of the workarounds for
> commonly seen behavior from bad sinks in intel_dp_dpcd_read_wake() to
> drm's DP helper.
> 
> Signed-off-by: Lyude <cpaul@redhat.com>
> ---
>  drivers/gpu/drm/drm_dp_helper.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
> index 7d58f59..d1128fb 100644
> --- a/drivers/gpu/drm/drm_dp_helper.c
> +++ b/drivers/gpu/drm/drm_dp_helper.c
> @@ -160,7 +160,7 @@ int drm_dp_bw_code_to_link_rate(u8 link_bw)
>  }
>  EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate);
>  
> -#define AUX_RETRY_INTERVAL 500 /* us */
> +#define AUX_RETRY_INTERVAL 1000 /* us */

Was this to adapt to the msleep(1) in the i915 function? If so it's kinda
wrong anyway, since an msleep(1) actually sleeps 1 jiffy, and on most
systems that's a lot more than 1 ms. If it all still works, I'd just drop
this patch here. I suspect that the magic is all in the more aggressive
retrying and the throwaway read, not in how long we actually wait.

On patches 2-5: Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

>  
>  /**
>   * DOC: dp helpers
> -- 
> 2.5.5
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
cpaul@redhat.com March 29, 2016, 2:05 p.m. UTC | #2
Yep, the rest of the patchset works fine without this patch

On Tue, 2016-03-29 at 10:27 +0200, Daniel Vetter wrote:
> On Mon, Mar 28, 2016 at 10:33:22AM -0400, Lyude wrote:
> > 
> > This is part of a patch series to migrate all of the workarounds for
> > commonly seen behavior from bad sinks in intel_dp_dpcd_read_wake() to
> > drm's DP helper.
> > 
> > Signed-off-by: Lyude <cpaul@redhat.com>
> > ---
> >  drivers/gpu/drm/drm_dp_helper.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_dp_helper.c
> > b/drivers/gpu/drm/drm_dp_helper.c
> > index 7d58f59..d1128fb 100644
> > --- a/drivers/gpu/drm/drm_dp_helper.c
> > +++ b/drivers/gpu/drm/drm_dp_helper.c
> > @@ -160,7 +160,7 @@ int drm_dp_bw_code_to_link_rate(u8 link_bw)
> >  }
> >  EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate);
> >  
> > -#define AUX_RETRY_INTERVAL 500 /* us */
> > +#define AUX_RETRY_INTERVAL 1000 /* us */
> Was this to adapt to the msleep(1) in the i915 function? If so it's kinda
> wrong anyway, since an msleep(1) actually sleeps 1 jiffy, and on most
> systems that's a lot more than 1 ms. If it all still works, I'd just drop
> this patch here. I suspect that the magic is all in the more aggressive
> retrying and the throwaway read, not in how long we actually wait.
> 
> On patches 2-5: Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> 
> > 
> >  
> >  /**
> >   * DOC: dp helpers
> > -- 
> > 2.5.5
> > 
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
diff mbox

Patch

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 7d58f59..d1128fb 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -160,7 +160,7 @@  int drm_dp_bw_code_to_link_rate(u8 link_bw)
 }
 EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate);
 
-#define AUX_RETRY_INTERVAL 500 /* us */
+#define AUX_RETRY_INTERVAL 1000 /* us */
 
 /**
  * DOC: dp helpers