<html><body><p> <pre> On Thu, 2024-07-18 at 16:49 +0800, Chen-Yu Tsai wrote: > > External email : Please do not click links or open attachments until > you have verified the sender or the content. > (CC-ed Fei Shao) > > On Thu, Jul 18, 2024 at 4:24 PM AngeloGioacchino Del Regno > <angelogioacchino.delregno@collabora.com> wrote: > > > > Hardware-speaking, there is no feature-reduced cursor specific > > plane, so this driver reserves the last all Overlay plane as a > > Cursor plane, but sets the maximum cursor width/height to the > > maximum value that the full overlay plane can use. > > > > While this could be ok, it raises issues with common userspace > > using libdrm (especially Mutter, but other compositors too) which > > will crash upon performing allocations and/or using said cursor > > plane. > > > > Reduce the maximum width/height for the cursor to 512x512 pixels, > > value taken from IGT's maximum cursor size test, which succeeds. > > > > Fixes: a4c9410b31ca ("drm/mediatek: Set DRM mode configs > accordingly") > > Signed-off-by: AngeloGioacchino Del Regno < > angelogioacchino.delregno@collabora.com> > > --- > > drivers/gpu/drm/mediatek/mtk_drm_drv.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c > b/drivers/gpu/drm/mediatek/mtk_drm_drv.c > > index 6f0b415a978d..b96763664c4f 100644 > > --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c > > +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c > > @@ -540,8 +540,8 @@ static int mtk_drm_kms_init(struct drm_device > *drm) > > } > > > > /* IGT will check if the cursor size is configured */ > > - drm->mode_config.cursor_width = drm->mode_config.max_width; > > - drm->mode_config.cursor_height = drm- > >mode_config.max_height; > > + drm->mode_config.cursor_width = 512; > > + drm->mode_config.cursor_height = 512; > > Fei already did the same (?) workaround downstream just recently. > > OOTH, Intel recently added a feature for enumerating "suggested" > cursor sizes. See https://patchwork.freedesktop.org/patch/583299/ > > Not sure if other compositors will end up using it or not. > > ChenYu > > > /* Use OVL device for all DMA memory allocations */ > > crtc = drm_crtc_from_index(drm, 0); > > -- > > 2.45.2 > > Just for more information, as the driver is describing the hardware limitation, and the comments for cursor_width/cursor_height in struct drm_mode_config indicates "hint to userspace for 'max' cursor width/height". After few discussions with the reviewer, we eventually set it to the maximum size the Overlay supports (d46f652fc9fde61d7e88bfeace62f27847d55d40.camel@mediatek.com>). Not sure if it makes sense for these userspace compositors to always use the maximum size of the cursor plane as the cursor size. Regards, Shawn </pre> </p></body></html><pre>************* MEDIATEK Confidentiality Notice ******************** The information contained in this e-mail message (including any attachments) may be confidential, proprietary, privileged, or otherwise exempt from disclosure under applicable laws. It is intended to be conveyed only to the designated recipient(s). Any use, dissemination, distribution, printing, retaining or copying of this e-mail (including its attachments) by unintended recipient(s) is strictly prohibited and may be unlawful. If you are not an intended recipient of this e-mail, or believe that you have received this e-mail in error, please notify the sender immediately (by replying to this e-mail), delete any and all copies of this e-mail (including any attachments) from your system, and do not disclose the content of this e-mail to any other person. Thank you! </pre>