Re: [Freedreno] [PATCH] drm/msm: use proper memory barriers for updating tail/head

2017-10-03 Thread Daniel Vetter
On Tue, Oct 3, 2017 at 2:59 PM, Rob Clark wrote: > On Tue, Oct 3, 2017 at 4:08 AM, Daniel Vetter wrote: >> On Mon, Oct 02, 2017 at 10:37:11AM -0400, Rob Clark wrote: >>> Fixes intermittent corruption of cmdstream dump. >>> >>> Signed-off-by: Rob Clark >> >> Rule of memory barriers: They always n

Re: [Freedreno] [PATCH] drm/msm: use proper memory barriers for updating tail/head

2017-10-03 Thread Rob Clark
On Tue, Oct 3, 2017 at 4:08 AM, Daniel Vetter wrote: > On Mon, Oct 02, 2017 at 10:37:11AM -0400, Rob Clark wrote: >> Fixes intermittent corruption of cmdstream dump. >> >> Signed-off-by: Rob Clark > > Rule of memory barriers: They always need to come in pairs, and you should > put a comment to ea

Re: [Freedreno] [PATCH] drm/msm: use proper memory barriers for updating tail/head

2017-10-03 Thread Daniel Vetter
On Mon, Oct 02, 2017 at 10:37:11AM -0400, Rob Clark wrote: > Fixes intermittent corruption of cmdstream dump. > > Signed-off-by: Rob Clark Rule of memory barriers: They always need to come in pairs, and you should put a comment to each one explaining where the other side is. I.e. for all the sto