| Message ID | 1395758972-31316-2-git-send-email-damien.lespiau@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Mar 25, 2014 at 02:49:30PM +0000, Damien Lespiau wrote: > Those fields are supposed to be a good default value for the cursor > size, intended for the case where the hardware doesn't support 64x64 > cursors, for use with a hw agnostic DDX driver for instance. > > We're fine with 64x64 cursors though and don't need to set those fields > (DRM core will return 64 is we don't). If we declare 256x256, that > generic driver will use a big buffer for the cursor, without any good > reason. How does userspace now know that 256x256 cursors are support for HiDPI? -Chris
On Tue, Mar 25, 2014 at 02:54:56PM +0000, Chris Wilson wrote: > On Tue, Mar 25, 2014 at 02:49:30PM +0000, Damien Lespiau wrote: > > Those fields are supposed to be a good default value for the cursor > > size, intended for the case where the hardware doesn't support 64x64 > > cursors, for use with a hw agnostic DDX driver for instance. > > > > We're fine with 64x64 cursors though and don't need to set those fields > > (DRM core will return 64 is we don't). If we declare 256x256, that > > generic driver will use a big buffer for the cursor, without any good > > reason. > > How does userspace now know that 256x256 cursors are support for HiDPI? It doesn't currently? a property on the cursor plane with the list of supported formats in the brave new full drm_plane world seems like a good option to me.
On Tue, Mar 25, 2014 at 02:59:18PM +0000, Damien Lespiau wrote: > On Tue, Mar 25, 2014 at 02:54:56PM +0000, Chris Wilson wrote: > > On Tue, Mar 25, 2014 at 02:49:30PM +0000, Damien Lespiau wrote: > > > Those fields are supposed to be a good default value for the cursor > > > size, intended for the case where the hardware doesn't support 64x64 > > > cursors, for use with a hw agnostic DDX driver for instance. > > > > > > We're fine with 64x64 cursors though and don't need to set those fields > > > (DRM core will return 64 is we don't). If we declare 256x256, that > > > generic driver will use a big buffer for the cursor, without any good > > > reason. > > > > How does userspace now know that 256x256 cursors are support for HiDPI? > > It doesn't currently? a property on the cursor plane with the list of > supported formats in the brave new full drm_plane world seems like a > good option to me. Userspace currently uses this method to determine the largest cursor supported by the driver. That userspace is inept at resize the cursor bo as required is a probably that won't be solved by simply exposing it later. -Chris
On Tue, 2014-03-25 at 14:49 +0000, Damien Lespiau wrote: > Those fields are supposed to be a good default value for the cursor > size, intended for the case where the hardware doesn't support 64x64 > cursors, for use with a hw agnostic DDX driver for instance. > > We're fine with 64x64 cursors though and don't need to set those fields > (DRM core will return 64 is we don't). If we declare 256x256, that > generic driver will use a big buffer for the cursor, without any good > reason. > > Cc: Sagar Kamble <sagar.a.kamble@intel.com> > Cc: Imre Deak <imre.deak@intel.com> > Signed-off-by: Damien Lespiau <damien.lespiau@intel.com> > --- > drivers/gpu/drm/i915/intel_display.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c > index 80dd1c2..7a47657 100644 > --- a/drivers/gpu/drm/i915/intel_display.c > +++ b/drivers/gpu/drm/i915/intel_display.c > @@ -10557,8 +10557,6 @@ static void intel_crtc_init(struct drm_device *dev, int pipe) > intel_crtc->max_cursor_width = CURSOR_WIDTH; > intel_crtc->max_cursor_height = CURSOR_HEIGHT; > } > - dev->mode_config.cursor_width = intel_crtc->max_cursor_width; > - dev->mode_config.cursor_height = intel_crtc->max_cursor_height; I thought drm_getcap should return the max cursor size, using these two fields. --Imre > > drm_mode_crtc_set_gamma_size(&intel_crtc->base, 256); > for (i = 0; i < 256; i++) {
On Tue, 2014-03-25 at 14:59 +0000, Damien Lespiau wrote: > On Tue, Mar 25, 2014 at 02:54:56PM +0000, Chris Wilson wrote: > > On Tue, Mar 25, 2014 at 02:49:30PM +0000, Damien Lespiau wrote: > > > Those fields are supposed to be a good default value for the cursor > > > size, intended for the case where the hardware doesn't support 64x64 > > > cursors, for use with a hw agnostic DDX driver for instance. > > > > > > We're fine with 64x64 cursors though and don't need to set those fields > > > (DRM core will return 64 is we don't). If we declare 256x256, that > > > generic driver will use a big buffer for the cursor, without any good > > > reason. > > > > How does userspace now know that 256x256 cursors are support for HiDPI? > > It doesn't currently? a property on the cursor plane with the list of > supported formats in the brave new full drm_plane world seems like a > good option to me. How do we handle cursor size cap that was added with http://lists.freedesktop.org/archives/dri-devel/2014-February/053770.html. Will change i-g-t kms_cursor_crc accordingly as well since it depends on this cap. >
On Tue, Mar 25, 2014 at 03:09:16PM +0000, Chris Wilson wrote: > On Tue, Mar 25, 2014 at 02:59:18PM +0000, Damien Lespiau wrote: > > On Tue, Mar 25, 2014 at 02:54:56PM +0000, Chris Wilson wrote: > > > On Tue, Mar 25, 2014 at 02:49:30PM +0000, Damien Lespiau wrote: > > > > Those fields are supposed to be a good default value for the cursor > > > > size, intended for the case where the hardware doesn't support 64x64 > > > > cursors, for use with a hw agnostic DDX driver for instance. > > > > > > > > We're fine with 64x64 cursors though and don't need to set those fields > > > > (DRM core will return 64 is we don't). If we declare 256x256, that > > > > generic driver will use a big buffer for the cursor, without any good > > > > reason. > > > > > > How does userspace now know that 256x256 cursors are support for HiDPI? > > > > It doesn't currently? a property on the cursor plane with the list of > > supported formats in the brave new full drm_plane world seems like a > > good option to me. > > Userspace currently uses this method to determine the largest cursor > supported by the driver. That userspace is inept at resize the cursor bo > as required is a probably that won't be solved by simply exposing it > later. That doesn't seem to be the intention of the original patch? http://lists.freedesktop.org/archives/dri-devel/2014-February/053770.html Are you saying the Intel DDX currently derives a different meaning to the intented behaviour? in which case it can still be changed to not do that?
On Tue, Mar 25, 2014 at 04:05:29PM +0000, Damien Lespiau wrote: > On Tue, Mar 25, 2014 at 03:09:16PM +0000, Chris Wilson wrote: > > On Tue, Mar 25, 2014 at 02:59:18PM +0000, Damien Lespiau wrote: > > > On Tue, Mar 25, 2014 at 02:54:56PM +0000, Chris Wilson wrote: > > > > On Tue, Mar 25, 2014 at 02:49:30PM +0000, Damien Lespiau wrote: > > > > > Those fields are supposed to be a good default value for the cursor > > > > > size, intended for the case where the hardware doesn't support 64x64 > > > > > cursors, for use with a hw agnostic DDX driver for instance. > > > > > > > > > > We're fine with 64x64 cursors though and don't need to set those fields > > > > > (DRM core will return 64 is we don't). If we declare 256x256, that > > > > > generic driver will use a big buffer for the cursor, without any good > > > > > reason. > > > > > > > > How does userspace now know that 256x256 cursors are support for HiDPI? > > > > > > It doesn't currently? a property on the cursor plane with the list of > > > supported formats in the brave new full drm_plane world seems like a > > > good option to me. > > > > Userspace currently uses this method to determine the largest cursor > > supported by the driver. That userspace is inept at resize the cursor bo > > as required is a probably that won't be solved by simply exposing it > > later. > > That doesn't seem to be the intention of the original patch? > > http://lists.freedesktop.org/archives/dri-devel/2014-February/053770.html For the record, 16:30 < agd5f> ickle, our GPUs don't have selectable cursor sizes 16:31 < agd5f> so on the newer ones, xf86-video-modesetting, etc. would allocate a 64x64 cursor and it would look squashed and funky since the hw expects 128x128 Which means I was confused when I thought part of the reasoning was indeed HiDPI support. (I'm still seem to remember that was part of the argument for large cursors anyway.) > Are you saying the Intel DDX currently derives a different meaning to > the intented behaviour? in which case it can still be changed to not do > that? I still disagree though. This provides all the information I need to support variable sized cursors and we can use large cursors today. -Chris
On Tue, Mar 25, 2014 at 04:38:24PM +0000, Chris Wilson wrote: > For the record, > > 16:30 < agd5f> ickle, our GPUs don't have selectable cursor sizes > 16:31 < agd5f> so on the newer ones, xf86-video-modesetting, etc. would > allocate a 64x64 cursor and it would look squashed and funky since the > hw expects 128x128 > > Which means I was confused when I thought part of the reasoning was > indeed HiDPI support. (I'm still seem to remember that was part of the > argument for large cursors anyway.) > > > Are you saying the Intel DDX currently derives a different meaning to > > the intented behaviour? in which case it can still be changed to not do > > that? > > I still disagree though. This provides all the information I need to > support variable sized cursors and we can use large cursors today. I'd love the game to be about defining clear semantics more than "by interpreting that value this way, I got what I always wanted" :) We can resolve that today with MAX_CURSOR_WIDTH, MAX_CURSOR_HEIGHT caps as well (if you're alluding at the fact that drm_planes may still be a few decades away). We'll still need to expose the full list of supported cursor sizes for compositors at some point or another, my preferred way would be with a property in the exposed cursor drm_plane.
On Tue, Mar 25, 2014 at 04:38:24PM +0000, Chris Wilson wrote: > > Are you saying the Intel DDX currently derives a different meaning to > > the intented behaviour? in which case it can still be changed to not do > > that? > > I still disagree though. This provides all the information I need to > support variable sized cursors and we can use large cursors today. Note that I won't fight if you find it useful and people are fine with that new meaning. Can we just throw a patch actually documented what you want those values to be? The WM patch still needs to take the actual cursor size though. Keeping those global limits on the crtc struct still looks weird.
On Tue, Mar 25, 2014 at 04:57:04PM +0000, Damien Lespiau wrote: > On Tue, Mar 25, 2014 at 04:38:24PM +0000, Chris Wilson wrote: > > For the record, > > > > 16:30 < agd5f> ickle, our GPUs don't have selectable cursor sizes > > 16:31 < agd5f> so on the newer ones, xf86-video-modesetting, etc. would > > allocate a 64x64 cursor and it would look squashed and funky since the > > hw expects 128x128 > > > > Which means I was confused when I thought part of the reasoning was > > indeed HiDPI support. (I'm still seem to remember that was part of the > > argument for large cursors anyway.) > > > > > Are you saying the Intel DDX currently derives a different meaning to > > > the intented behaviour? in which case it can still be changed to not do > > > that? > > > > I still disagree though. This provides all the information I need to > > support variable sized cursors and we can use large cursors today. > > I'd love the game to be about defining clear semantics more than "by > interpreting that value this way, I got what I always wanted" :) > > We can resolve that today with MAX_CURSOR_WIDTH, MAX_CURSOR_HEIGHT caps > as well (if you're alluding at the fact that drm_planes may still be a > few decades away). > > We'll still need to expose the full list of supported cursor sizes for > compositors at some point or another, my preferred way would be with a > property in the exposed cursor drm_plane. For the record I'll restate my comment here about the larger problem: Atm we have no way for userspace to figure out per-plane limits on sizes/strides, we only expose a lists of supported pixel formats. Imo exposing cursor limits is just part of this larger issue, so if we can get the current stuff working with some legalese, then I'm ok with that. Solving the larger issue is much more work, and it's better to have a few more odd cases working than not. For planes I guess we could have a few limits: min/max width height in pixels min/max stride alignment of stride And a pile of flags - needs pot stride/width/height - needs square size That should be enough to cover most single-plane things. For multiplanar I guess we might either just need 2nd/3rd set of those or some additional stuff expressed in flags (e.g. subsampled strides must be half of the Y stride). Or we'll throw our hands in the air for multi-planar for now ;-) Or we simply do this per-pixel format with one for each framebuffer plane, i.e. struct drm_get_plane_fb_limits { uint32_t plane_id; /* in */ uint32_t fourcc; /* in */ struct drm_plane_limits limits[MAX_FOURCC_PLANES]; /* the stuff above for all possible planes of a fourcc code */ } Saner drivers could then return the same thing for all fourccs codes in their backend. Just something to ponder. Adding dri-devel, maybe we can get this discussion started. -Daniel
On Tue, Mar 25, 2014 at 07:23:26PM +0100, Daniel Vetter wrote: > On Tue, Mar 25, 2014 at 04:57:04PM +0000, Damien Lespiau wrote: > > On Tue, Mar 25, 2014 at 04:38:24PM +0000, Chris Wilson wrote: > > > For the record, > > > > > > 16:30 < agd5f> ickle, our GPUs don't have selectable cursor sizes > > > 16:31 < agd5f> so on the newer ones, xf86-video-modesetting, etc. would > > > allocate a 64x64 cursor and it would look squashed and funky since the > > > hw expects 128x128 > > > > > > Which means I was confused when I thought part of the reasoning was > > > indeed HiDPI support. (I'm still seem to remember that was part of the > > > argument for large cursors anyway.) > > > > > > > Are you saying the Intel DDX currently derives a different meaning to > > > > the intented behaviour? in which case it can still be changed to not do > > > > that? > > > > > > I still disagree though. This provides all the information I need to > > > support variable sized cursors and we can use large cursors today. > > > > I'd love the game to be about defining clear semantics more than "by > > interpreting that value this way, I got what I always wanted" :) > > > > We can resolve that today with MAX_CURSOR_WIDTH, MAX_CURSOR_HEIGHT caps > > as well (if you're alluding at the fact that drm_planes may still be a > > few decades away). > > > > We'll still need to expose the full list of supported cursor sizes for > > compositors at some point or another, my preferred way would be with a > > property in the exposed cursor drm_plane. > > For the record I'll restate my comment here about the larger problem: > > Atm we have no way for userspace to figure out per-plane limits on > sizes/strides, we only expose a lists of supported pixel formats. > > Imo exposing cursor limits is just part of this larger issue, so if we can > get the current stuff working with some legalese, then I'm ok with that. > Solving the larger issue is much more work, and it's better to have a few > more odd cases working than not. For planes I guess we could have a few > limits: > > min/max width height in pixels > min/max stride > alignment of stride > > And a pile of flags > - needs pot stride/width/height > - needs square size Already new ones: - stride must match width*bpp This will be fun if we ever do it ... -Daniel > > That should be enough to cover most single-plane things. For multiplanar I > guess we might either just need 2nd/3rd set of those or some additional > stuff expressed in flags (e.g. subsampled strides must be half of the Y > stride). Or we'll throw our hands in the air for multi-planar for now ;-) > > Or we simply do this per-pixel format with one for each framebuffer plane, > i.e. > > struct drm_get_plane_fb_limits { > uint32_t plane_id; /* in */ > uint32_t fourcc; /* in */ > struct drm_plane_limits limits[MAX_FOURCC_PLANES]; > /* the stuff above for all possible planes of a fourcc code */ > } > > Saner drivers could then return the same thing for all fourccs codes in > their backend. > > Just something to ponder. > > Adding dri-devel, maybe we can get this discussion started. > -Daniel > -- > Daniel Vetter > Software Engineer, Intel Corporation > +41 (0) 79 365 57 48 - http://blog.ffwll.ch
On Tue, Mar 25, 2014 at 07:23:26PM +0100, Daniel Vetter wrote: > Or we simply do this per-pixel format with one for each framebuffer plane, > i.e. > > struct drm_get_plane_fb_limits { > uint32_t plane_id; /* in */ > uint32_t fourcc; /* in */ > struct drm_plane_limits limits[MAX_FOURCC_PLANES]; > /* the stuff above for all possible planes of a fourcc code */ > } > > Saner drivers could then return the same thing for all fourccs codes in > their backend. Some of the limits are definitely per format. Plane max dimensions are a good example of a limit that can change per-format (8bpp Vs 10bpp to be contained within the same max bandwidth of the hw).
On Tue, Mar 25, 2014 at 7:51 PM, Damien Lespiau <damien.lespiau@intel.com> wrote: > On Tue, Mar 25, 2014 at 07:23:26PM +0100, Daniel Vetter wrote: >> Or we simply do this per-pixel format with one for each framebuffer plane, >> i.e. >> >> struct drm_get_plane_fb_limits { >> uint32_t plane_id; /* in */ >> uint32_t fourcc; /* in */ >> struct drm_plane_limits limits[MAX_FOURCC_PLANES]; >> /* the stuff above for all possible planes of a fourcc code */ >> } >> >> Saner drivers could then return the same thing for all fourccs codes in >> their backend. > > Some of the limits are definitely per format. Plane max dimensions are a > good example of a limit that can change per-format (8bpp Vs 10bpp to be > contained within the same max bandwidth of the hw). One thing I've completely missed btw is scaling limits. How we then need to factor in bandwidth I have no idea about ... I guess at one point it boils down to "try it and give up if it doesn't work". And I think we need a few scaling related flags like "can't scale at all" or sub-sampling restrictions. Who knows ... -Daniel
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 80dd1c2..7a47657 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -10557,8 +10557,6 @@ static void intel_crtc_init(struct drm_device *dev, int pipe) intel_crtc->max_cursor_width = CURSOR_WIDTH; intel_crtc->max_cursor_height = CURSOR_HEIGHT; } - dev->mode_config.cursor_width = intel_crtc->max_cursor_width; - dev->mode_config.cursor_height = intel_crtc->max_cursor_height; drm_mode_crtc_set_gamma_size(&intel_crtc->base, 256); for (i = 0; i < 256; i++) {
Those fields are supposed to be a good default value for the cursor size, intended for the case where the hardware doesn't support 64x64 cursors, for use with a hw agnostic DDX driver for instance. We're fine with 64x64 cursors though and don't need to set those fields (DRM core will return 64 is we don't). If we declare 256x256, that generic driver will use a big buffer for the cursor, without any good reason. Cc: Sagar Kamble <sagar.a.kamble@intel.com> Cc: Imre Deak <imre.deak@intel.com> Signed-off-by: Damien Lespiau <damien.lespiau@intel.com> --- drivers/gpu/drm/i915/intel_display.c | 2 -- 1 file changed, 2 deletions(-)