On Thu, Feb 20, 2020 at 1:44 AM James Hughes james.hughes@raspberrypi.com wrote:
On Wed, 19 Feb 2020 at 22:51, Eric Anholt eric@anholt.net wrote:
On Mon, Feb 17, 2020 at 7:41 AM James Hughes james.hughes@raspberrypi.com wrote:
The wait_for macro's for Broadcom VC4 and V3D drivers used msleep which is inappropriate due to its inaccuracy at low values (minimum wait time is about 30ms on the Raspberry Pi).
This patch replaces the macro with the one from the Intel i915 version which uses usleep_range to provide more accurate waits.
Signed-off-by: James Hughes james.hughes@raspberrypi.com
To apply this, we're going to want to split the patch up between v3d (with a fixes tag to the introduction of the driver, since it's a pretty critical fix) and vc4 (where it's used in KMS, and we're pretty sure we want it but changing timing like this in KMS paths is risky so we don't want to backport to stable). And adjust the commit messages to have consistent prefixes to the rest of the commits to those drivers.
I've been fighting with the drm maintainer tools today to try to apply the patch, with no luck. I'll keep trying, and if I succeed, I'll push it.
Hi Eric,
unclear whether you want me to do the split or whether you are going to (your last paragraph). Also I'm a bit unclear on the exact requirements for the prefixes etc.
I debugged what was going on with my maintainer tools and got the patches applied:
https://cgit.freedesktop.org/drm/drm-misc/commit/?id=9daee6141cc9c75b09659b0... https://cgit.freedesktop.org/drm/drm-misc/commit/?id=7f2a09ecf2e8d86e22598df...
Apologies for the wait! I've fixed some mail filters I think so I should notice pings like this in the future. But also I hope Maxime can feel enabled to merge patches to vc4/v3d in the future -- I certainly don't want to be the limiting factor here, and it's under drm-misc so any drm-misc maintainer can apply stuff.