On Fri, May 04, 2018 at 11:19:45PM +0300, Ville Syrjälä wrote:
> On Thu, May 03, 2018 at 08:26:26AM +0200, Daniel Vetter wrote:
> > On Wed, May 02, 2018 at 12:20:20PM +0530, Nautiyal, Ankit K wrote:
> > > From: Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx>
> > >
> > > We parse the EDID and add all the modes in the connector's modelist.
> > > This adds CEA modes with aspect ratio information too, regardless of
> > > whether user space requested this information or not.
> > >
> > > This patch:
> > > -prunes the modes with aspect-ratio information, from a
> > > connector's modelist, if the user-space has not set the aspect ratio
> > > DRM client cap. However if such a mode is unique in the list, it is
> > > kept in the list, with aspect-ratio flags reset.
> > > -prepares a list of exposed modes, which is used to find unique modes
> > > if aspect-ratio is not allowed.
> > > -adds a new list_head 'exposed_head' in drm_mode_display, to traverse
> > > the list of exposed modes.
> > >
> > > Cc: Ville Syrjala <ville.syrjala@xxxxxxxxxxxxxxx>
> > > Cc: Shashank Sharma <shashank.sharma@xxxxxxxxx>
> > > Cc: Jose Abreu <jose.abreu@xxxxxxxxxxxx>
> > >
> > > Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx>
> > >
> > > V3: As suggested by Ville, modified the mechanism of pruning of modes
> > > with aspect-ratio, if the aspect-ratio is not supported. Instead
> > > of straight away pruning such a mode, the mode is retained with
> > > aspect ratio bits set to zero, provided it is unique.
> > > V4: rebase
> > > V5: Addressed review comments from Ville:
> > > -used a pointer to store last valid mode.
> > > -avoided, modifying of picture_aspect_ratio in kernel mode,
> > > instead only flags bits of user mode are reset (if aspect-ratio
> > > is not supported).
> > > V6: As suggested by Ville, corrected the mode pruning logic and
> > > elaborated the mode pruning logic and the assumptions taken.
> > > V7: rebase
> > > V8: rebase
> > > V9: rebase
> > > V10: rebase
> > > V11: Fixed the issue caused in kms_3d test, and enhanced the pruning
> > > logic to correctly identify and prune modes with aspect-ratio,
> > > if aspect-ratio cap is not set.
> > > V12: As suggested by Ville, added another list_head in
> > > drm_mode_display to traverse the list of exposed modes and
> > > avoided duplication of modes.
> > > V13: Minor modifications, as suggested by Ville.
> > > ---
> > > drivers/gpu/drm/drm_connector.c | 45 ++++++++++++++++++++++++++++++++++-------
> > > include/drm/drm_modes.h | 13 ++++++++++++
> > > 2 files changed, 51 insertions(+), 7 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> > > index dfc8ca1..8ca1149 100644
> > > --- a/drivers/gpu/drm/drm_connector.c
> > > +++ b/drivers/gpu/drm/drm_connector.c
> > > @@ -1531,15 +1531,36 @@ static struct drm_encoder *drm_connector_get_encoder(struct drm_connector *conne
> > > return connector->encoder;
> > > }
> > >
> > > -static bool drm_mode_expose_to_userspace(const struct drm_display_mode *mode,
> > > - const struct drm_file *file_priv)
> > > +static bool
> > > +drm_mode_expose_to_userspace(const struct drm_display_mode *mode,
> > > + const struct list_head *export_list,
> > > + const struct drm_file *file_priv)
> > > {
> > > /*
> > > * If user-space hasn't configured the driver to expose the stereo 3D
> > > * modes, don't expose them.
> > > */
> > > +
> > > if (!file_priv->stereo_allowed && drm_mode_is_stereo(mode))
> > > return false;
> > > + /*
> > > + * If user-space hasn't configured the driver to expose the modes
> > > + * with aspect-ratio, don't expose them. However if such a mode
> > > + * is unique, let it be exposed, but reset the aspect-ratio flags
> > > + * while preparing the list of user-modes.
> > > + */
> > > + if (!file_priv->aspect_ratio_allowed &&
> > > + mode->picture_aspect_ratio != HDMI_PICTURE_ASPECT_NONE) {
> > > + struct drm_display_mode *mode_itr;
> > > +
> > > + list_for_each_entry(mode_itr, export_list, export_head)
> >
> > By walking the list of only the modes already added to the export list we
> > rely on ASPECT_NONE being first if present. That seems to be a bit
> > fragile. If we instead walk over all present modes (i.e. connector->modes)
> > then I think that's avoided.
>
> I don't think that would work. If we just walk over all the modes then
> wouldn't we always find a duplicate when the same mode with two different
> aspect ratios is on the list? And then we'd export neither? Or maybe I
> misunderstood what you mean here.
We'd export both. Let's assume we have 2 modes, only difference is aspect
ratio.
1. We check the first mode, it has aspect_ratio != NONE. But because
there's no other exported mode yet on export_list, we export it (and
filter out the aspect_ratio by setting it to NONE).
2. 2nd mode has aspect_ratio == NONE, so we export it.
Results in duped modes exported. If you always guarantee that aspect_ratio
== NONE is before the same mode with aspect ratio, then this algo here
works. But not for the more general case I think.
> To me it seems like the correct option is to check against the
> export_list unconditionally, no matter whether the current mode has the
> aspect ratio set or not. If an identical mode is already on the list
> we don't export again, if it's not there then we export.
That might be another option to fix the bug.
-Daniel
>
> > With that changed:
> >
> > Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
> >
> > > + if (drm_mode_match(mode_itr, mode,
> > > + DRM_MODE_MATCH_TIMINGS |
> > > + DRM_MODE_MATCH_CLOCK |
> > > + DRM_MODE_MATCH_FLAGS |
> > > + DRM_MODE_MATCH_3D_FLAGS))
> > > + return false;
> > > + }
> > >
> > > return true;
> > > }
> > > @@ -1559,6 +1580,7 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
> > > struct drm_mode_modeinfo u_mode;
> > > struct drm_mode_modeinfo __user *mode_ptr;
> > > uint32_t __user *encoder_ptr;
> > > + LIST_HEAD(export_list);
> > >
> > > if (!drm_core_check_feature(dev, DRIVER_MODESET))
> > > return -EINVAL;
> > > @@ -1607,21 +1629,30 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
> > >
> > > /* delayed so we get modes regardless of pre-fill_modes state */
> > > list_for_each_entry(mode, &connector->modes, head)
> > > - if (drm_mode_expose_to_userspace(mode, file_priv))
> > > + if (drm_mode_expose_to_userspace(mode, &export_list,
> > > + file_priv)) {
> > > + list_add_tail(&mode->export_head, &export_list);
> > > mode_count++;
> > > + }
> > >
> > > /*
> > > * This ioctl is called twice, once to determine how much space is
> > > * needed, and the 2nd time to fill it.
> > > + * The modes that need to be exposed to the user are maintained in the
> > > + * 'export_list'. When the ioctl is called first time to determine the,
> > > + * space, the export_list gets filled, to find the no.of modes. In the
> > > + * 2nd time, the user modes are filled, one by one from the export_list.
> > > */
> > > if ((out_resp->count_modes >= mode_count) && mode_count) {
> > > copied = 0;
> > > mode_ptr = (struct drm_mode_modeinfo __user *)(unsigned long)out_resp->modes_ptr;
> > > - list_for_each_entry(mode, &connector->modes, head) {
> > > - if (!drm_mode_expose_to_userspace(mode, file_priv))
> > > - continue;
> > > -
> > > + list_for_each_entry(mode, &export_list, export_head) {
> > > drm_mode_convert_to_umode(&u_mode, mode);
> > > + /*
> > > + * Reset aspect ratio flags of user-mode, if modes with
> > > + * aspect-ratio are not supported.
> > > + */
> > > + drm_mode_filter_aspect_ratio_flags(file_priv, &u_mode);
> > > if (copy_to_user(mode_ptr + copied,
> > > &u_mode, sizeof(u_mode))) {
> > > ret = -EFAULT;
> > > diff --git a/include/drm/drm_modes.h b/include/drm/drm_modes.h
> > > index 2f78b7e..b159fe0 100644
> > > --- a/include/drm/drm_modes.h
> > > +++ b/include/drm/drm_modes.h
> > > @@ -411,6 +411,19 @@ struct drm_display_mode {
> > > * Field for setting the HDMI picture aspect ratio of a mode.
> > > */
> > > enum hdmi_picture_aspect picture_aspect_ratio;
> > > +
> > > + /**
> > > + * @export_head:
> > > + *
> > > + * struct list_head for modes to be exposed to the userspace.
> > > + * This is to maintain a list of exposed modes while preparing
> > > + * user-mode's list in drm_mode_getconnector ioctl. The purpose of this
> > > + * list_head only lies in the ioctl function, and is not expected to be
> > > + * used outside the function.
> > > + * Once used, the stale pointers are not reset, but left as it is, to
> > > + * avoid overhead of protecting it by mode_config.mutex.
> > > + */
> > > + struct list_head export_head;
> > > };
> > >
> > > /**
> > > --
> > > 2.7.4
> > >
> > > _______________________________________________
> > > dri-devel mailing list
> > > dri-devel@xxxxxxxxxxxxxxxxxxxxx
> > > https://lists.freedesktop.org/mailman/listinfo/dri-devel
> >
> > --
> > Daniel Vetter
> > Software Engineer, Intel Corporation
> > http://blog.ffwll.ch
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel@xxxxxxxxxxxxxxxxxxxxx
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
>
> --
> Ville Syrjälä
> Intel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
