在 2021/8/2 下午10:51, Alex Deucher 写道: > On Mon, Aug 2, 2021 at 4:31 AM Daniel Vetter wrote: >> On Mon, Aug 02, 2021 at 10:12:47AM +0200, Christian König wrote: >>> Am 02.08.21 um 09:43 schrieb Zhenneng Li: >>>> When primary bo is updated, crtc's pitch may >>>> have not been updated, this will lead to show >>>> disorder content when user changes display mode, >>>> we update crtc's pitch in page flip to avoid >>>> this bug. >>>> This refers to amdgpu's pageflip. >>> Alex is the expert to ask about that code, but I'm not sure if that is >>> really correct for the old hardware. >>> >>> As far as I know the crtc's pitch should not change during a page flip, but >>> only during a full mode set. >>> >>> So could you elaborate a bit more how you trigger this? >> legacy page_flip ioctl only verifies that the fb->format stays the same. >> It doesn't check anything else (afair never has), this is all up to >> drivers to verify. >> >> Personally I'd say add a check to reject this, since testing this and >> making sure it really works everywhere is probably a bit much on this old >> hw. > If just the pitch changed, that probably wouldn't be much of a > problem, but if the pitch is changing, that probably implies other > stuff has changed as well and we'll just be chasing changes. I agree > it would be best to just reject anything other than updating the > scanout address. Thanks for your reply!  In theory , pitch is updated only when the scanout address is updated,  but we can trigger this bug on r5230 when using two screens and changing modeset,  you can execute shell: #!/bin/bash cnt=0; while [ 1 ] do xrandr --output HDMI-0 --right-of VGA-0 --auto echo "hdmi----vga" sleep  8 xrandr --output VGA-0 --auto --output HDMI-0 --off sleep 3 let cnt+=1; echo $cnt done at the same time, open a new terminal, press F11 to fast switch this window between maximize size and normal size to improve the possibility，attachement picture shows the phenomenon. I add some debug messages: [   89.065206] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:589, set->crtc->primary->fb: 0xffffffa0e5956100, set->fb: 0xffffffa0e701e400 [   89.065209] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:601 [   89.065213] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:713, fb_changed: 1, mode_changed: 0 [   89.065216] lzn debug, drivers/gpu/drm/radeon/atombios_crtc.c:dce4_crtc_do_set_base:1148, x: 0: y: 0, crtc: 0xffffffa0e62dc000, atomic: 0 [   89.065222] lzn debug, drivers/gpu/drm/radeon/atombios_crtc.c:dce4_crtc_do_set_base:1426, fb_location: 0x117f2000, target_fb->width: 1920, target_fb->height: 1080 [   89.065223] lzn debug, drivers/gpu/drm/radeon/atombios_crtc.c:dce4_crtc_do_set_base:1430, fb_pitch_pixels: 1920, target_fb->pitches[0]: 7680, target_fb->format->cpp[0]: 4 [   89.065240] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:752***************************************************************** [   92.079288] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:589, set->crtc->primary->fb: 0xffffffa0e701e400, set->fb: 0xffffffa0eafced00 [   92.079291] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:601 [   92.079295] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:713, fb_changed: 1, mode_changed: 0 [   92.079298] lzn debug, drivers/gpu/drm/radeon/atombios_crtc.c:dce4_crtc_do_set_base:1148, x: 0: y: 0, crtc: 0xffffffa0e62dc000, atomic: 0 [   92.079304] lzn debug, drivers/gpu/drm/radeon/atombios_crtc.c:dce4_crtc_do_set_base:1426, fb_location: 0x10000000, target_fb->width: 3840, target_fb->height: 1080 [   92.079306] lzn debug, drivers/gpu/drm/radeon/atombios_crtc.c:dce4_crtc_do_set_base:1430, fb_pitch_pixels: 3840, target_fb->pitches[0]: 15360, target_fb->format->cpp[0]: 4 [   92.079323] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:752***************************************************************** [   92.080382] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:589, set->crtc->primary->fb: 0x0, set->fb: 0xffffffa0eafced00 [   92.080384] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:595 [   92.080387] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:713, fb_changed: 0, mode_changed: 1 [   92.080389] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:715 [   92.083143] lzn debug, drivers/gpu/drm/radeon/atombios_crtc.c:dce4_crtc_do_set_base:1148, x: 1920: y: 0, crtc: 0xffffffa0e62db000, atomic: 0 [   92.083149] lzn debug, drivers/gpu/drm/radeon/atombios_crtc.c:dce4_crtc_do_set_base:1426, fb_location: 0x10000000, target_fb->width: 3840, target_fb->height: 1080 [   92.083164] lzn debug, drivers/gpu/drm/radeon/atombios_crtc.c:dce4_crtc_do_set_base:1430, fb_pitch_pixels: 3840, target_fb->pitches[0]: 15360, target_fb->format->cpp[0]: 4 [   92.120595] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:752***************************************************************** [  100.157744] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:589, set->crtc->primary->fb: 0xffffffa0eafced00, set->fb: 0xffffffa0f3a5bb00 [  100.157746] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:601 [  100.157749] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:713, fb_changed: 1, mode_changed: 0 [  100.157752] lzn debug, drivers/gpu/drm/radeon/atombios_crtc.c:dce4_crtc_do_set_base:1148, x: 0: y: 0, crtc: 0xffffffa0e62dc000, atomic: 0 [  100.157758] lzn debug, drivers/gpu/drm/radeon/atombios_crtc.c:dce4_crtc_do_set_base:1426, fb_location: 0x1790c000, target_fb->width: 1920, target_fb->height: 1080 [  100.157760] lzn debug, drivers/gpu/drm/radeon/atombios_crtc.c:dce4_crtc_do_set_base:1430, fb_pitch_pixels: 1920, target_fb->pitches[0]: 7680, target_fb->format->cpp[0]: 4 [  100.157777] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:752***************************************************************** [  103.166751] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:589, set->crtc->primary->fb: 0xffffffa0e9a0cd00, set->fb: 0xffffffa0e9a0cd00 [  103.166757] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:713, fb_changed: 0, mode_changed: 0 [  103.166758] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:752***************************************************************** [  103.169353] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:589, set->crtc->primary->fb: 0x0, set->fb: 0xffffffa0e9a0cd00 [  103.169355] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:595 [  103.169359] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:713, fb_changed: 0, mode_changed: 1 [  103.169360] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:715 [  103.170396] lzn debug, drivers/gpu/drm/radeon/atombios_crtc.c:dce4_crtc_do_set_base:1148, x: 1920: y: 0, crtc: 0xffffffa0e62db000, atomic: 0 [  103.170403] lzn debug, drivers/gpu/drm/radeon/atombios_crtc.c:dce4_crtc_do_set_base:1426, fb_location: 0x11fea000, target_fb->width: 3840, target_fb->height: 1080 [  103.170404] lzn debug, drivers/gpu/drm/radeon/atombios_crtc.c:dce4_crtc_do_set_base:1430, fb_pitch_pixels: 3840, target_fb->pitches[0]: 15360, target_fb->format->cpp[0]: 4 [  103.224592] lzn debug, drivers/gpu/drm/drm_crtc_helper.c:drm_crtc_helper_set_config:752***************************************************************** After 103s of os started,  bug is triggerd, fb_changed and mode_changed are zero, and crtc's pitch has not been updated. Amdgpu has the same problem,  but amdgpu's page_flip will update pitch, so this bug can't trigger on amdgpu. you can refer to dce_v6_0_page_flip in amdgpu，all amdgpu drivers update pitch in page_flip. test os: focal-desktop-arm64.iso Zhenneng Li > > Alex > >> -Daniel >> >>> Thanks, >>> Christian. >>> >>>> Cc: Alex Deucher >>>> Cc: "Christian König" >>>> Cc: "Pan, Xinhui" >>>> Cc: David Airlie >>>> Cc: Daniel Vetter >>>> Cc: amd-gfx@lists.freedesktop.org >>>> Cc: dri-devel@lists.freedesktop.org >>>> Cc: linux-kernel@vger.kernel.org >>>> Signed-off-by: Zhenneng Li >>>> --- >>>> drivers/gpu/drm/radeon/evergreen.c | 8 +++++++- >>>> 1 file changed, 7 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c >>>> index 36a888e1b179..eeb590d2dec2 100644 >>>> --- a/drivers/gpu/drm/radeon/evergreen.c >>>> +++ b/drivers/gpu/drm/radeon/evergreen.c >>>> @@ -28,6 +28,7 @@ >>>> #include >>>> #include >>>> +#include >>>> #include "atom.h" >>>> #include "avivod.h" >>>> @@ -1414,10 +1415,15 @@ void evergreen_page_flip(struct radeon_device *rdev, int crtc_id, u64 crtc_base, >>>> bool async) >>>> { >>>> struct radeon_crtc *radeon_crtc = rdev->mode_info.crtcs[crtc_id]; >>>> + struct drm_framebuffer *fb = radeon_crtc->base.primary->fb; >>>> - /* update the scanout addresses */ >>>> + /* flip at hsync for async, default is vsync */ >>>> WREG32(EVERGREEN_GRPH_FLIP_CONTROL + radeon_crtc->crtc_offset, >>>> async ? EVERGREEN_GRPH_SURFACE_UPDATE_H_RETRACE_EN : 0); >>>> + /* update pitch */ >>>> + WREG32(EVERGREEN_GRPH_PITCH + radeon_crtc->crtc_offset, >>>> + fb->pitches[0] / fb->format->cpp[0]); >>>> + /* update the scanout addresses */ >>>> WREG32(EVERGREEN_GRPH_PRIMARY_SURFACE_ADDRESS_HIGH + radeon_crtc->crtc_offset, >>>> upper_32_bits(crtc_base)); >>>> WREG32(EVERGREEN_GRPH_PRIMARY_SURFACE_ADDRESS + radeon_crtc->crtc_offset, >>>> >>>> No virus found >>>> Checked by Hillstone Network AntiVirus >> -- >> Daniel Vetter >> Software Engineer, Intel Corporation >> http://blog.ffwll.ch