On 07/07/2020 08:03, Gerd Hoffmann wrote:
Yes, that's correct - I can confirm that the simplified diff below works:
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 5609e164805f..83af05fac604 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -399,7 +399,7 @@ static void drm_fb_helper_dirty_blit_real(struct drm_fb_helper *fb_helper, unsigned int y;
for (y = clip->y1; y < clip->y2; y++) {
memcpy(dst, src, len);
fb_memcpy_tofb(dst, src, len);fb_memcpy_tofb is #defined to sbus_memcpy_toio @ sparc which looks wrong to me given that this is a pci not a sbus device. sparc also has memcpy_toio which looks better to me.
There are blit helpers in drm_format_helper.c which already use memcpy_toio(), I guess we should do the same here. Not fully sure we can use memcpy_toio() unconditionally here. Given that a shadow framebuffer makes sense only in case the real framebuffer is not in normal ram we probably can.
Thanks Gerd - I've just tested the diff below with memcpy_toio() and that works too:
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 5609e164805f..4d05b0ab1592 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -399,7 +399,7 @@ static void drm_fb_helper_dirty_blit_real(struct drm_fb_helper *fb_helper, unsigned int y;
for (y = clip->y1; y < clip->y2; y++) { - memcpy(dst, src, len); + memcpy_toio(dst, src, len); src += fb->pitches[0]; dst += fb->pitches[0]; }
Presumably there is some existing mechanism that ensures SPARC will always choose a shadow framebuffer?
ATB,
Mark.