| Message ID | 1461856717-6476-4-git-send-email-noralf@tronnes.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On 28/04/16 18:18, Noralf Trønnes wrote: > This adds deferred io support to drm_fb_helper. > The fbdev framebuffer changes are flushed using the callback > (struct drm_framebuffer *)->funcs->dirty() by a dedicated worker > ensuring that it always runs in process context. > > Signed-off-by: Noralf Trønnes <noralf@tronnes.org> > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> > --- Thanks for the series! Unfortunately I haven't been able to follow the discussions properly, so I hope my questions haven't been covered earlier. > Changes since v3: > - Don't use forward decl, move drm_fb_helper_dirty_work() > - Use DIV_ROUND_UP in drm_fb_helper_deferred_io() > > Changes since v2: > - FB_DEFERRED_IO is now always selected by DRM_KMS_FB_HELPER, ifdef removed > - The drm_clip_rect utility functions are dropped, so open code it > - docs: use & to denote structs > > Changes since v1: > - Use a dedicated worker to run the framebuffer flushing like qxl does > - Add parameter descriptions to drm_fb_helper_deferred_io > > drivers/gpu/drm/Kconfig | 1 + > drivers/gpu/drm/drm_fb_helper.c | 103 +++++++++++++++++++++++++++++++++++++++- > include/drm/drm_fb_helper.h | 15 ++++++ > 3 files changed, 118 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig > index 9e4f2f1..8e6f34b 100644 > --- a/drivers/gpu/drm/Kconfig > +++ b/drivers/gpu/drm/Kconfig > @@ -52,6 +52,7 @@ config DRM_KMS_FB_HELPER > select FB_CFB_FILLRECT > select FB_CFB_COPYAREA > select FB_CFB_IMAGEBLIT > + select FB_DEFERRED_IO > help > FBDEV helpers for KMS drivers. > > diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c > index 855108e..62f849f 100644 > --- a/drivers/gpu/drm/drm_fb_helper.c > +++ b/drivers/gpu/drm/drm_fb_helper.c > @@ -84,6 +84,15 @@ static LIST_HEAD(kernel_fb_helper_list); > * and set up an initial configuration using the detected hardware, drivers > * should call drm_fb_helper_single_add_all_connectors() followed by > * drm_fb_helper_initial_config(). > + * > + * If CONFIG_FB_DEFERRED_IO is enabled and &drm_framebuffer_funcs ->dirty is > + * set, the drm_fb_helper_{cfb,sys}_{write,fillrect,copyarea,imageblit} > + * functions will accumulate changes and schedule &fb_helper .dirty_work to run > + * right away. This worker then calls the dirty() function ensuring that it > + * will always run in process context since the fb_*() function could be > + * running in atomic context. If drm_fb_helper_deferred_io() is used as the Who's calling {write,fillrect,copyarea,imageblit} in an atomic context? That sounds like a very bad idea to me... If this is only for accumulating changes, I think it may be better to leave that to the driver as it may have better idea of how to accumulate. But, of course, this is a helper, so if all the drivers use this kind of accumulation, it makes sense =). Tomi
Den 29.04.2016 14:50, skrev Tomi Valkeinen: > Hi, > > On 28/04/16 18:18, Noralf Trønnes wrote: >> This adds deferred io support to drm_fb_helper. >> The fbdev framebuffer changes are flushed using the callback >> (struct drm_framebuffer *)->funcs->dirty() by a dedicated worker >> ensuring that it always runs in process context. >> >> Signed-off-by: Noralf Trønnes <noralf@tronnes.org> >> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> >> --- > Thanks for the series! Unfortunately I haven't been able to follow the > discussions properly, so I hope my questions haven't been covered earlier. > >> Changes since v3: >> - Don't use forward decl, move drm_fb_helper_dirty_work() >> - Use DIV_ROUND_UP in drm_fb_helper_deferred_io() >> >> Changes since v2: >> - FB_DEFERRED_IO is now always selected by DRM_KMS_FB_HELPER, ifdef removed >> - The drm_clip_rect utility functions are dropped, so open code it >> - docs: use & to denote structs >> >> Changes since v1: >> - Use a dedicated worker to run the framebuffer flushing like qxl does >> - Add parameter descriptions to drm_fb_helper_deferred_io >> >> drivers/gpu/drm/Kconfig | 1 + >> drivers/gpu/drm/drm_fb_helper.c | 103 +++++++++++++++++++++++++++++++++++++++- >> include/drm/drm_fb_helper.h | 15 ++++++ >> 3 files changed, 118 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig >> index 9e4f2f1..8e6f34b 100644 >> --- a/drivers/gpu/drm/Kconfig >> +++ b/drivers/gpu/drm/Kconfig >> @@ -52,6 +52,7 @@ config DRM_KMS_FB_HELPER >> select FB_CFB_FILLRECT >> select FB_CFB_COPYAREA >> select FB_CFB_IMAGEBLIT >> + select FB_DEFERRED_IO >> help >> FBDEV helpers for KMS drivers. >> >> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c >> index 855108e..62f849f 100644 >> --- a/drivers/gpu/drm/drm_fb_helper.c >> +++ b/drivers/gpu/drm/drm_fb_helper.c >> @@ -84,6 +84,15 @@ static LIST_HEAD(kernel_fb_helper_list); >> * and set up an initial configuration using the detected hardware, drivers >> * should call drm_fb_helper_single_add_all_connectors() followed by >> * drm_fb_helper_initial_config(). >> + * >> + * If CONFIG_FB_DEFERRED_IO is enabled and &drm_framebuffer_funcs ->dirty is >> + * set, the drm_fb_helper_{cfb,sys}_{write,fillrect,copyarea,imageblit} >> + * functions will accumulate changes and schedule &fb_helper .dirty_work to run >> + * right away. This worker then calls the dirty() function ensuring that it >> + * will always run in process context since the fb_*() function could be >> + * running in atomic context. If drm_fb_helper_deferred_io() is used as the > Who's calling {write,fillrect,copyarea,imageblit} in an atomic context? > That sounds like a very bad idea to me... I haven't verified it myself, but took it as fact based on commit: bcb39af4486be07e896fc374a2336bad3104ae0a drm/udl: make usage as a console safer Okay you don't really want to use udl devices as your console, but if you are unlucky enough to do so, you run into a lot of schedule while atomic due to printk being called from all sorts of funky places. So check if we are in an atomic context, and queue the damage for later, the next printk should cause it to appear. This isn't ideal, but it is simple, and seems to work okay in my testing here. (dirty area idea came from xenfb) fixes a bunch of sleeping while atomic issues running fbcon on udl devices. Cc: stable@vger.kernel.org Signed-off-by: Dave Airlie <airlied@redhat.com> > If this is only for accumulating changes, I think it may be better to > leave that to the driver as it may have better idea of how to accumulate. > > But, of course, this is a helper, so if all the drivers use this kind of > accumulation, it makes sense =). qxl already accumulates damage this way and upcoming tinydrm also. udl has handled this damage inline except when in_atomic() which results in damage being deferred to the next fb_*() call. It is possible for drivers to have their own fb_*() handling and still use drm_fb_helper_deferred_io(). For those who likes details, this is fbcon unblanking which results in a full display update on a 320x240 display, shell with blinking cursor on the last line of the console: [ 5505.164150] drm_fb_helper_dirty: x=152,width=8,y=224,height=16 [ 5505.164186] [drm:drm_atomic_state_init] Allocated atomic state b859e400 [...more drm atomic msgs...] [ 5505.164713] drm_fb_helper_dirty: x=152,width=8,y=224,height=16 [ 5505.164746] [drm:drm_atomic_state_init] Allocated atomic state b859e440 [...more drm atomic msgs...] [ 5505.165086] drm_fb_helper_dirty: x=0,width=320,y=0,height=16 [ 5505.165153] drm_fb_helper_dirty: x=0,width=320,y=16,height=16 [ 5505.165220] drm_fb_helper_dirty: x=0,width=320,y=32,height=16 [ 5505.165287] drm_fb_helper_dirty: x=0,width=320,y=48,height=16 [ 5505.165354] drm_fb_helper_dirty: x=0,width=320,y=64,height=16 [ 5505.165420] drm_fb_helper_dirty: x=0,width=320,y=80,height=16 [ 5505.165487] drm_fb_helper_dirty: x=0,width=320,y=96,height=16 [ 5505.165553] drm_fb_helper_dirty: x=0,width=320,y=112,height=16 [ 5505.165619] drm_fb_helper_dirty: x=0,width=320,y=128,height=16 [ 5505.165686] drm_fb_helper_dirty: x=0,width=320,y=144,height=16 [ 5505.165752] drm_fb_helper_dirty: x=0,width=320,y=160,height=16 [ 5505.165818] drm_fb_helper_dirty: x=0,width=320,y=176,height=16 [ 5505.165884] drm_fb_helper_dirty: x=0,width=320,y=192,height=16 [ 5505.165949] drm_fb_helper_dirty: x=0,width=320,y=208,height=16 [ 5505.165978] drm_fb_helper_dirty: x=0,width=112,y=224,height=16 [ 5505.165988] drm_fb_helper_dirty: x=112,width=8,y=224,height=16 [ 5505.166002] drm_fb_helper_dirty: x=120,width=24,y=224,height=16 [ 5505.166041] drm_fb_helper_dirty: x=144,width=176,y=224,height=16 [ 5505.166058] drm_fb_helper_dirty: x=152,width=8,y=224,height=16 [ 5505.166079] drm_fb_helper_dirty: x=152,width=8,y=224,height=16 [ 5505.166424] drm_fb_helper_dirty_work: x1=0,x2=320,y1=0,y2=240 [ 5505.166452] adafruit-tft spi0.0: mipi_dbi_dirtyfb: vmem=bac40000, x1=0, x2=320, y1=0, y2=240 Cursor blinking: [ 5505.363478] drm_fb_helper_dirty: x=152,width=8,y=224,height=16 [ 5505.363509] drm_fb_helper_dirty_work: x1=152,x2=160,y1=224,y2=240 [ 5505.363539] adafruit-tft spi0.0: mipi_dbi_dirtyfb: vmem=bac40000, x1=152, x2=160, y1=224, y2=240 [ 5505.563488] drm_fb_helper_dirty: x=152,width=8,y=224,height=16 [ 5505.563514] drm_fb_helper_dirty_work: x1=152,x2=160,y1=224,y2=240 [ 5505.563542] adafruit-tft spi0.0: mipi_dbi_dirtyfb: vmem=bac40000, x1=152, x2=160, y1=224, y2=240 Noralf. -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Apr 29, 2016 at 03:50:40PM +0300, Tomi Valkeinen wrote: > Hi, > > On 28/04/16 18:18, Noralf Trønnes wrote: > > This adds deferred io support to drm_fb_helper. > > The fbdev framebuffer changes are flushed using the callback > > (struct drm_framebuffer *)->funcs->dirty() by a dedicated worker > > ensuring that it always runs in process context. > > > > Signed-off-by: Noralf Trønnes <noralf@tronnes.org> > > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> > > --- > > Thanks for the series! Unfortunately I haven't been able to follow the > discussions properly, so I hope my questions haven't been covered earlier. > > > Changes since v3: > > - Don't use forward decl, move drm_fb_helper_dirty_work() > > - Use DIV_ROUND_UP in drm_fb_helper_deferred_io() > > > > Changes since v2: > > - FB_DEFERRED_IO is now always selected by DRM_KMS_FB_HELPER, ifdef removed > > - The drm_clip_rect utility functions are dropped, so open code it > > - docs: use & to denote structs > > > > Changes since v1: > > - Use a dedicated worker to run the framebuffer flushing like qxl does > > - Add parameter descriptions to drm_fb_helper_deferred_io > > > > drivers/gpu/drm/Kconfig | 1 + > > drivers/gpu/drm/drm_fb_helper.c | 103 +++++++++++++++++++++++++++++++++++++++- > > include/drm/drm_fb_helper.h | 15 ++++++ > > 3 files changed, 118 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig > > index 9e4f2f1..8e6f34b 100644 > > --- a/drivers/gpu/drm/Kconfig > > +++ b/drivers/gpu/drm/Kconfig > > @@ -52,6 +52,7 @@ config DRM_KMS_FB_HELPER > > select FB_CFB_FILLRECT > > select FB_CFB_COPYAREA > > select FB_CFB_IMAGEBLIT > > + select FB_DEFERRED_IO > > help > > FBDEV helpers for KMS drivers. > > > > diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c > > index 855108e..62f849f 100644 > > --- a/drivers/gpu/drm/drm_fb_helper.c > > +++ b/drivers/gpu/drm/drm_fb_helper.c > > @@ -84,6 +84,15 @@ static LIST_HEAD(kernel_fb_helper_list); > > * and set up an initial configuration using the detected hardware, drivers > > * should call drm_fb_helper_single_add_all_connectors() followed by > > * drm_fb_helper_initial_config(). > > + * > > + * If CONFIG_FB_DEFERRED_IO is enabled and &drm_framebuffer_funcs ->dirty is > > + * set, the drm_fb_helper_{cfb,sys}_{write,fillrect,copyarea,imageblit} > > + * functions will accumulate changes and schedule &fb_helper .dirty_work to run > > + * right away. This worker then calls the dirty() function ensuring that it > > + * will always run in process context since the fb_*() function could be > > + * running in atomic context. If drm_fb_helper_deferred_io() is used as the > > Who's calling {write,fillrect,copyarea,imageblit} in an atomic context? > That sounds like a very bad idea to me... > > If this is only for accumulating changes, I think it may be better to > leave that to the driver as it may have better idea of how to accumulate. > > But, of course, this is a helper, so if all the drivers use this kind of > accumulation, it makes sense =). Apparently panic context and cursor timer and stuff like that. I think this started with udl, and just to make sure (it's fbdev after all, no one wants to read the code itself) we've put those checks onto all entry points that draw stuff. It could be overkill, but this is what udl/qxl already do, so better to keep imo for now. I guess if it's really not needed we could later on change that, but not sure that's worth the effort. And we can't get rid of it entirely. -Daniel
On 29/04/16 17:55, Daniel Vetter wrote: >> Who's calling {write,fillrect,copyarea,imageblit} in an atomic context? >> That sounds like a very bad idea to me... >> >> If this is only for accumulating changes, I think it may be better to >> leave that to the driver as it may have better idea of how to accumulate. >> >> But, of course, this is a helper, so if all the drivers use this kind of >> accumulation, it makes sense =). > > Apparently panic context and cursor timer and stuff like that. I think > this started with udl, and just to make sure (it's fbdev after all, no one > wants to read the code itself) we've put those checks onto all entry > points that draw stuff. It could be overkill, but this is what udl/qxl > already do, so better to keep imo for now. > > I guess if it's really not needed we could later on change that, but not > sure that's worth the effort. And we can't get rid of it entirely. Yep... Sounds fine to me. Someone should implement (minimal) fbdev userspace API support to DRM without using the current fbdev, and implement fbcon on top of that. I don't like how DRM and fbdev gets mixed... I offer a beer to anyone who does that =). Tomi
On Fri, Apr 29, 2016 at 06:00:18PM +0300, Tomi Valkeinen wrote: > > On 29/04/16 17:55, Daniel Vetter wrote: > > >> Who's calling {write,fillrect,copyarea,imageblit} in an atomic context? > >> That sounds like a very bad idea to me... > >> > >> If this is only for accumulating changes, I think it may be better to > >> leave that to the driver as it may have better idea of how to accumulate. > >> > >> But, of course, this is a helper, so if all the drivers use this kind of > >> accumulation, it makes sense =). > > > > Apparently panic context and cursor timer and stuff like that. I think > > this started with udl, and just to make sure (it's fbdev after all, no one > > wants to read the code itself) we've put those checks onto all entry > > points that draw stuff. It could be overkill, but this is what udl/qxl > > already do, so better to keep imo for now. > > > > I guess if it's really not needed we could later on change that, but not > > sure that's worth the effort. And we can't get rid of it entirely. > > Yep... Sounds fine to me. > > Someone should implement (minimal) fbdev userspace API support to DRM > without using the current fbdev, and implement fbcon on top of that. I > don't like how DRM and fbdev gets mixed... > > I offer a beer to anyone who does that =). The big plan that has been floated years back already (before David Herrmann disappeared into the rh systemd gang) was to have a pure userspace kmscon for console (including vt-switching in userspace like X does), plus a super-minimal panic console on top of kms in the kernel. That looked like a really solid design, unfornutately it didn't go anywhere. But basic patches are still around, and it really just boils down to that some distro would need to integrate kmscon properly, and polish of the kernel side too for integration. -Daniel
Adding David, forgot that before hitting send. -Daniel On Fri, Apr 29, 2016 at 5:36 PM, Daniel Vetter <daniel@ffwll.ch> wrote: > On Fri, Apr 29, 2016 at 06:00:18PM +0300, Tomi Valkeinen wrote: >> >> On 29/04/16 17:55, Daniel Vetter wrote: >> >> >> Who's calling {write,fillrect,copyarea,imageblit} in an atomic context? >> >> That sounds like a very bad idea to me... >> >> >> >> If this is only for accumulating changes, I think it may be better to >> >> leave that to the driver as it may have better idea of how to accumulate. >> >> >> >> But, of course, this is a helper, so if all the drivers use this kind of >> >> accumulation, it makes sense =). >> > >> > Apparently panic context and cursor timer and stuff like that. I think >> > this started with udl, and just to make sure (it's fbdev after all, no one >> > wants to read the code itself) we've put those checks onto all entry >> > points that draw stuff. It could be overkill, but this is what udl/qxl >> > already do, so better to keep imo for now. >> > >> > I guess if it's really not needed we could later on change that, but not >> > sure that's worth the effort. And we can't get rid of it entirely. >> >> Yep... Sounds fine to me. >> >> Someone should implement (minimal) fbdev userspace API support to DRM >> without using the current fbdev, and implement fbcon on top of that. I >> don't like how DRM and fbdev gets mixed... >> >> I offer a beer to anyone who does that =). > > The big plan that has been floated years back already (before David > Herrmann disappeared into the rh systemd gang) was to have a pure > userspace kmscon for console (including vt-switching in userspace like X > does), plus a super-minimal panic console on top of kms in the kernel. > That looked like a really solid design, unfornutately it didn't go > anywhere. But basic patches are still around, and it really just boils > down to that some distro would need to integrate kmscon properly, and > polish of the kernel side too for integration. > -Daniel > -- > Daniel Vetter > Software Engineer, Intel Corporation > http://blog.ffwll.ch
On Fri, Apr 29, 2016 at 04:47:08PM +0200, Noralf Trønnes wrote: > > Den 29.04.2016 14:50, skrev Tomi Valkeinen: > >Hi, > > > >On 28/04/16 18:18, Noralf Trønnes wrote: > >>This adds deferred io support to drm_fb_helper. > >>The fbdev framebuffer changes are flushed using the callback > >>(struct drm_framebuffer *)->funcs->dirty() by a dedicated worker > >>ensuring that it always runs in process context. > >> > >>Signed-off-by: Noralf Trønnes <noralf@tronnes.org> > >>Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> > >>--- > >Thanks for the series! Unfortunately I haven't been able to follow the > >discussions properly, so I hope my questions haven't been covered earlier. > > > >>Changes since v3: > >>- Don't use forward decl, move drm_fb_helper_dirty_work() > >>- Use DIV_ROUND_UP in drm_fb_helper_deferred_io() > >> > >>Changes since v2: > >>- FB_DEFERRED_IO is now always selected by DRM_KMS_FB_HELPER, ifdef removed > >>- The drm_clip_rect utility functions are dropped, so open code it > >>- docs: use & to denote structs > >> > >>Changes since v1: > >>- Use a dedicated worker to run the framebuffer flushing like qxl does > >>- Add parameter descriptions to drm_fb_helper_deferred_io > >> > >> drivers/gpu/drm/Kconfig | 1 + > >> drivers/gpu/drm/drm_fb_helper.c | 103 +++++++++++++++++++++++++++++++++++++++- > >> include/drm/drm_fb_helper.h | 15 ++++++ > >> 3 files changed, 118 insertions(+), 1 deletion(-) > >> > >>diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig > >>index 9e4f2f1..8e6f34b 100644 > >>--- a/drivers/gpu/drm/Kconfig > >>+++ b/drivers/gpu/drm/Kconfig > >>@@ -52,6 +52,7 @@ config DRM_KMS_FB_HELPER > >> select FB_CFB_FILLRECT > >> select FB_CFB_COPYAREA > >> select FB_CFB_IMAGEBLIT > >>+ select FB_DEFERRED_IO > >> help > >> FBDEV helpers for KMS drivers. > >> > >>diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c > >>index 855108e..62f849f 100644 > >>--- a/drivers/gpu/drm/drm_fb_helper.c > >>+++ b/drivers/gpu/drm/drm_fb_helper.c > >>@@ -84,6 +84,15 @@ static LIST_HEAD(kernel_fb_helper_list); > >> * and set up an initial configuration using the detected hardware, drivers > >> * should call drm_fb_helper_single_add_all_connectors() followed by > >> * drm_fb_helper_initial_config(). > >>+ * > >>+ * If CONFIG_FB_DEFERRED_IO is enabled and &drm_framebuffer_funcs ->dirty is > >>+ * set, the drm_fb_helper_{cfb,sys}_{write,fillrect,copyarea,imageblit} > >>+ * functions will accumulate changes and schedule &fb_helper .dirty_work to run > >>+ * right away. This worker then calls the dirty() function ensuring that it > >>+ * will always run in process context since the fb_*() function could be > >>+ * running in atomic context. If drm_fb_helper_deferred_io() is used as the > >Who's calling {write,fillrect,copyarea,imageblit} in an atomic context? > >That sounds like a very bad idea to me... > > I haven't verified it myself, but took it as fact based on > commit: bcb39af4486be07e896fc374a2336bad3104ae0a I've added a citation to this commit as the reason why we need to handle atomic, to make sure Tomi's question is answered for posterity. -Daniel > > drm/udl: make usage as a console safer > Okay you don't really want to use udl devices as your console, but if > you are unlucky enough to do so, you run into a lot of schedule while atomic > due to printk being called from all sorts of funky places. So check if we > are in an atomic context, and queue the damage for later, the next printk > should cause it to appear. This isn't ideal, but it is simple, and seems to > work okay in my testing here. > > (dirty area idea came from xenfb) > > fixes a bunch of sleeping while atomic issues running fbcon on udl devices. > > Cc: stable@vger.kernel.org > Signed-off-by: Dave Airlie <airlied@redhat.com> > > >If this is only for accumulating changes, I think it may be better to > >leave that to the driver as it may have better idea of how to accumulate. > > > >But, of course, this is a helper, so if all the drivers use this kind of > >accumulation, it makes sense =). > > qxl already accumulates damage this way and upcoming tinydrm also. > udl has handled this damage inline except when in_atomic() which results > in damage being deferred to the next fb_*() call. > > It is possible for drivers to have their own fb_*() handling and still > use drm_fb_helper_deferred_io(). > > > For those who likes details, this is fbcon unblanking which results in a > full display update on a 320x240 display, shell with blinking cursor on > the last line of the console: > > [ 5505.164150] drm_fb_helper_dirty: x=152,width=8,y=224,height=16 > [ 5505.164186] [drm:drm_atomic_state_init] Allocated atomic state b859e400 > [...more drm atomic msgs...] > [ 5505.164713] drm_fb_helper_dirty: x=152,width=8,y=224,height=16 > [ 5505.164746] [drm:drm_atomic_state_init] Allocated atomic state b859e440 > [...more drm atomic msgs...] > [ 5505.165086] drm_fb_helper_dirty: x=0,width=320,y=0,height=16 > [ 5505.165153] drm_fb_helper_dirty: x=0,width=320,y=16,height=16 > [ 5505.165220] drm_fb_helper_dirty: x=0,width=320,y=32,height=16 > [ 5505.165287] drm_fb_helper_dirty: x=0,width=320,y=48,height=16 > [ 5505.165354] drm_fb_helper_dirty: x=0,width=320,y=64,height=16 > [ 5505.165420] drm_fb_helper_dirty: x=0,width=320,y=80,height=16 > [ 5505.165487] drm_fb_helper_dirty: x=0,width=320,y=96,height=16 > [ 5505.165553] drm_fb_helper_dirty: x=0,width=320,y=112,height=16 > [ 5505.165619] drm_fb_helper_dirty: x=0,width=320,y=128,height=16 > [ 5505.165686] drm_fb_helper_dirty: x=0,width=320,y=144,height=16 > [ 5505.165752] drm_fb_helper_dirty: x=0,width=320,y=160,height=16 > [ 5505.165818] drm_fb_helper_dirty: x=0,width=320,y=176,height=16 > [ 5505.165884] drm_fb_helper_dirty: x=0,width=320,y=192,height=16 > [ 5505.165949] drm_fb_helper_dirty: x=0,width=320,y=208,height=16 > [ 5505.165978] drm_fb_helper_dirty: x=0,width=112,y=224,height=16 > [ 5505.165988] drm_fb_helper_dirty: x=112,width=8,y=224,height=16 > [ 5505.166002] drm_fb_helper_dirty: x=120,width=24,y=224,height=16 > [ 5505.166041] drm_fb_helper_dirty: x=144,width=176,y=224,height=16 > [ 5505.166058] drm_fb_helper_dirty: x=152,width=8,y=224,height=16 > [ 5505.166079] drm_fb_helper_dirty: x=152,width=8,y=224,height=16 > [ 5505.166424] drm_fb_helper_dirty_work: x1=0,x2=320,y1=0,y2=240 > [ 5505.166452] adafruit-tft spi0.0: mipi_dbi_dirtyfb: vmem=bac40000, x1=0, > x2=320, y1=0, y2=240 > > Cursor blinking: > > [ 5505.363478] drm_fb_helper_dirty: x=152,width=8,y=224,height=16 > [ 5505.363509] drm_fb_helper_dirty_work: x1=152,x2=160,y1=224,y2=240 > [ 5505.363539] adafruit-tft spi0.0: mipi_dbi_dirtyfb: vmem=bac40000, x1=152, > x2=160, y1=224, y2=240 > > [ 5505.563488] drm_fb_helper_dirty: x=152,width=8,y=224,height=16 > [ 5505.563514] drm_fb_helper_dirty_work: x1=152,x2=160,y1=224,y2=240 > [ 5505.563542] adafruit-tft spi0.0: mipi_dbi_dirtyfb: vmem=bac40000, x1=152, > x2=160, y1=224, y2=240 > > > Noralf. > >
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index 9e4f2f1..8e6f34b 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -52,6 +52,7 @@ config DRM_KMS_FB_HELPER select FB_CFB_FILLRECT select FB_CFB_COPYAREA select FB_CFB_IMAGEBLIT + select FB_DEFERRED_IO help FBDEV helpers for KMS drivers. diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 855108e..62f849f 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -84,6 +84,15 @@ static LIST_HEAD(kernel_fb_helper_list); * and set up an initial configuration using the detected hardware, drivers * should call drm_fb_helper_single_add_all_connectors() followed by * drm_fb_helper_initial_config(). + * + * If CONFIG_FB_DEFERRED_IO is enabled and &drm_framebuffer_funcs ->dirty is + * set, the drm_fb_helper_{cfb,sys}_{write,fillrect,copyarea,imageblit} + * functions will accumulate changes and schedule &fb_helper .dirty_work to run + * right away. This worker then calls the dirty() function ensuring that it + * will always run in process context since the fb_*() function could be + * running in atomic context. If drm_fb_helper_deferred_io() is used as the + * deferred_io callback it will also schedule dirty_work with the damage + * collected from the mmap page writes. */ /** @@ -637,6 +646,23 @@ static void drm_fb_helper_crtc_free(struct drm_fb_helper *helper) kfree(helper->crtc_info); } +static void drm_fb_helper_dirty_work(struct work_struct *work) +{ + struct drm_fb_helper *helper = container_of(work, struct drm_fb_helper, + dirty_work); + struct drm_clip_rect *clip = &helper->dirty_clip; + struct drm_clip_rect clip_copy; + unsigned long flags; + + spin_lock_irqsave(&helper->dirty_lock, flags); + clip_copy = *clip; + clip->x1 = clip->y1 = ~0; + clip->x2 = clip->y2 = 0; + spin_unlock_irqrestore(&helper->dirty_lock, flags); + + helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1); +} + /** * drm_fb_helper_prepare - setup a drm_fb_helper structure * @dev: DRM device @@ -650,6 +676,9 @@ void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper, const struct drm_fb_helper_funcs *funcs) { INIT_LIST_HEAD(&helper->kernel_fb_list); + spin_lock_init(&helper->dirty_lock); + INIT_WORK(&helper->dirty_work, drm_fb_helper_dirty_work); + helper->dirty_clip.x1 = helper->dirty_clip.y1 = ~0; helper->funcs = funcs; helper->dev = dev; } @@ -834,6 +863,59 @@ void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper) } EXPORT_SYMBOL(drm_fb_helper_unlink_fbi); +static void drm_fb_helper_dirty(struct fb_info *info, u32 x, u32 y, + u32 width, u32 height) +{ + struct drm_fb_helper *helper = info->par; + struct drm_clip_rect *clip = &helper->dirty_clip; + unsigned long flags; + + if (!helper->fb->funcs->dirty) + return; + + spin_lock_irqsave(&helper->dirty_lock, flags); + clip->x1 = min_t(u32, clip->x1, x); + clip->y1 = min_t(u32, clip->y1, y); + clip->x2 = max_t(u32, clip->x2, x + width); + clip->y2 = max_t(u32, clip->y2, y + height); + spin_unlock_irqrestore(&helper->dirty_lock, flags); + + schedule_work(&helper->dirty_work); +} + +/** + * drm_fb_helper_deferred_io() - fbdev deferred_io callback function + * @info: fb_info struct pointer + * @pagelist: list of dirty mmap framebuffer pages + * + * This function is used as the &fb_deferred_io ->deferred_io + * callback function for flushing the fbdev mmap writes. + */ +void drm_fb_helper_deferred_io(struct fb_info *info, + struct list_head *pagelist) +{ + unsigned long start, end, min, max; + struct page *page; + u32 y1, y2; + + min = ULONG_MAX; + max = 0; + list_for_each_entry(page, pagelist, lru) { + start = page->index << PAGE_SHIFT; + end = start + PAGE_SIZE - 1; + min = min(min, start); + max = max(max, end); + } + + if (min < max) { + y1 = min / info->fix.line_length; + y2 = min_t(u32, DIV_ROUND_UP(max, info->fix.line_length), + info->var.yres); + drm_fb_helper_dirty(info, 0, y1, info->var.xres, y2 - y1); + } +} +EXPORT_SYMBOL(drm_fb_helper_deferred_io); + /** * drm_fb_helper_sys_read - wrapper around fb_sys_read * @info: fb_info struct pointer @@ -862,7 +944,14 @@ EXPORT_SYMBOL(drm_fb_helper_sys_read); ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf, size_t count, loff_t *ppos) { - return fb_sys_write(info, buf, count, ppos); + ssize_t ret; + + ret = fb_sys_write(info, buf, count, ppos); + if (ret > 0) + drm_fb_helper_dirty(info, 0, 0, info->var.xres, + info->var.yres); + + return ret; } EXPORT_SYMBOL(drm_fb_helper_sys_write); @@ -877,6 +966,8 @@ void drm_fb_helper_sys_fillrect(struct fb_info *info, const struct fb_fillrect *rect) { sys_fillrect(info, rect); + drm_fb_helper_dirty(info, rect->dx, rect->dy, + rect->width, rect->height); } EXPORT_SYMBOL(drm_fb_helper_sys_fillrect); @@ -891,6 +982,8 @@ void drm_fb_helper_sys_copyarea(struct fb_info *info, const struct fb_copyarea *area) { sys_copyarea(info, area); + drm_fb_helper_dirty(info, area->dx, area->dy, + area->width, area->height); } EXPORT_SYMBOL(drm_fb_helper_sys_copyarea); @@ -905,6 +998,8 @@ void drm_fb_helper_sys_imageblit(struct fb_info *info, const struct fb_image *image) { sys_imageblit(info, image); + drm_fb_helper_dirty(info, image->dx, image->dy, + image->width, image->height); } EXPORT_SYMBOL(drm_fb_helper_sys_imageblit); @@ -919,6 +1014,8 @@ void drm_fb_helper_cfb_fillrect(struct fb_info *info, const struct fb_fillrect *rect) { cfb_fillrect(info, rect); + drm_fb_helper_dirty(info, rect->dx, rect->dy, + rect->width, rect->height); } EXPORT_SYMBOL(drm_fb_helper_cfb_fillrect); @@ -933,6 +1030,8 @@ void drm_fb_helper_cfb_copyarea(struct fb_info *info, const struct fb_copyarea *area) { cfb_copyarea(info, area); + drm_fb_helper_dirty(info, area->dx, area->dy, + area->width, area->height); } EXPORT_SYMBOL(drm_fb_helper_cfb_copyarea); @@ -947,6 +1046,8 @@ void drm_fb_helper_cfb_imageblit(struct fb_info *info, const struct fb_image *image) { cfb_imageblit(info, image); + drm_fb_helper_dirty(info, image->dx, image->dy, + image->width, image->height); } EXPORT_SYMBOL(drm_fb_helper_cfb_imageblit); diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h index 062723b..5b4aa35 100644 --- a/include/drm/drm_fb_helper.h +++ b/include/drm/drm_fb_helper.h @@ -172,6 +172,10 @@ struct drm_fb_helper_connector { * @funcs: driver callbacks for fb helper * @fbdev: emulated fbdev device info struct * @pseudo_palette: fake palette of 16 colors + * @dirty_clip: clip rectangle used with deferred_io to accumulate damage to + * the screen buffer + * @dirty_lock: spinlock protecting @dirty_clip + * @dirty_work: worker used to flush the framebuffer * * This is the main structure used by the fbdev helpers. Drivers supporting * fbdev emulation should embedded this into their overall driver structure. @@ -189,6 +193,9 @@ struct drm_fb_helper { const struct drm_fb_helper_funcs *funcs; struct fb_info *fbdev; u32 pseudo_palette[17]; + struct drm_clip_rect dirty_clip; + spinlock_t dirty_lock; + struct work_struct dirty_work; /** * @kernel_fb_list: @@ -245,6 +252,9 @@ void drm_fb_helper_fill_fix(struct fb_info *info, uint32_t pitch, void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper); +void drm_fb_helper_deferred_io(struct fb_info *info, + struct list_head *pagelist); + ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf, size_t count, loff_t *ppos); ssize_t drm_fb_helper_sys_write(struct fb_info *info, const char __user *buf, @@ -368,6 +378,11 @@ static inline void drm_fb_helper_unlink_fbi(struct drm_fb_helper *fb_helper) { } +static inline void drm_fb_helper_deferred_io(struct fb_info *info, + struct list_head *pagelist) +{ +} + static inline ssize_t drm_fb_helper_sys_read(struct fb_info *info, char __user *buf, size_t count, loff_t *ppos)