Am 10.01.20 um 22:30 schrieb Harry Wentland:
On 2020-01-10 4:16 p.m., Harry Wentland wrote:
On 2020-01-10 1:47 p.m., Liu, Zhan wrote:
-----Original Message-----
From: amd-gfx <amd-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of
Christian König
Sent: 2020/January/10, Friday 10:02 AM
To: Siqueira, Rodrigo <Rodrigo.Siqueira@xxxxxxx>; amd-
gfx@xxxxxxxxxxxxxxxxxxxxx
Cc: Li, Sun peng (Leo) <Sunpeng.Li@xxxxxxx>; Cheng, Tony
<Tony.Cheng@xxxxxxx>; Tsai, Martin <Martin.Tsai@xxxxxxx>; Lakha,
Bhawanpreet <Bhawanpreet.Lakha@xxxxxxx>; Wentland, Harry
<Harry.Wentland@xxxxxxx>
Subject: Re: [PATCH 39/43] drm/amd/display: Use udelay to avoid context
switch
Am 10.01.20 um 15:46 schrieb Rodrigo Siqueira:
From: Martin Tsai <martin.tsai@xxxxxxx>
[why]
The rapid msleep operation causes the white line garbage when DAL
check flip pending status in SetVidPnSourceVisibility.
To execute this msleep will induce context switch, and longer delay
could cause worse garbage situation.
[how]
To replace msleep with udelay.
Signed-off-by: Martin Tsai <martin.tsai@xxxxxxx>
Reviewed-by: Tony Cheng <Tony.Cheng@xxxxxxx>
Acked-by: Harry Wentland <harry.wentland@xxxxxxx>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@xxxxxxx>
---
drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
index 89920924a154..0dc652e76848 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c
@@ -1642,9 +1642,9 @@ void dcn20_program_front_end_for_ctx(
struct hubp *hubp = pipe->plane_res.hubp;
int j = 0;
- for (j = 0; j < TIMEOUT_FOR_PIPE_ENABLE_MS
+ for (j = 0; j < TIMEOUT_FOR_PIPE_ENABLE_MS*1000
&& hubp->funcs-
hubp_is_flip_pending(hubp); j++)
- msleep(1);
+ udelay(1);
Why not using mdelay() here?
As far as I know, mdelay() is only defined on Linux side.
This piece of code is shared by both Linux and Windows, so we have to use a function that's available on both platforms.
It was used here before so we definitely have it defined for Windows as
well.
Whoops, I misread that.
mdelay is indeed not defined on our other platforms but we could go
ahead and define it if needed.
Yes, indeed. And to repeat other platforms are irrelevant for up streaming.
When changing the code in a certain way for Linux makes sense then we
have do to this and need to adjust other platforms accordingly or
maintain the delta somehow.
Christian.
Harry
From the commit description it sounds like msleep wasn't tight enough
and longer delays lead to issues here, at least on Windows.
Martin, Tony, do you have more details about this?
Thanks,
Harry
Zhan
Christian.
}
}
_______________________________________________
amd-gfx mailing list
amd-gfx@xxxxxxxxxxxxxxxxxxxxx
_______________________________________________
amd-gfx mailing list
amd-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/amd-gfx
_______________________________________________
amd-gfx mailing list
amd-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/amd-gfx
