On Wed, Dec 20, 2017 at 10:35:43AM +0100, Maarten Lankhorst wrote: > lock_all_ctx in setplane_internal may return -EINTR, and > __setplane_internal could return -EDEADLK. Making more > special cases for fb would make the code even harder to > read, so the easiest solution is not taking over the fb > refcount, and making callers responsible for dropping > the ref. > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=102707 > Fixes: 13736ba3b38b ("drm/legacy: Convert setplane ioctl locking to interruptible.") > Testcase: kms_atomic_interruptible > Signed-off-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> I thought I reviewed this one before already, but probably just a paste somewhere on irc. Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx> > --- > drivers/gpu/drm/drm_plane.c | 42 ++++++++++++++++++++---------------------- > 1 file changed, 20 insertions(+), 22 deletions(-) > > diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c > index 37a93cdffb4a..2c90519576a3 100644 > --- a/drivers/gpu/drm/drm_plane.c > +++ b/drivers/gpu/drm/drm_plane.c > @@ -558,11 +558,10 @@ int drm_plane_check_pixel_format(const struct drm_plane *plane, u32 format) > } > > /* > - * setplane_internal - setplane handler for internal callers > + * __setplane_internal - setplane handler for internal callers > * > - * Note that we assume an extra reference has already been taken on fb. If the > - * update fails, this reference will be dropped before return; if it succeeds, > - * the previous framebuffer (if any) will be unreferenced instead. > + * This function will take a reference on the new fb for the plane > + * on success. > * > * src_{x,y,w,h} are provided in 16.16 fixed point format > */ > @@ -630,14 +629,12 @@ static int __setplane_internal(struct drm_plane *plane, > if (!ret) { > plane->crtc = crtc; > plane->fb = fb; > - fb = NULL; > + drm_framebuffer_get(plane->fb); > } else { > plane->old_fb = NULL; > } > > out: > - if (fb) > - drm_framebuffer_put(fb); > if (plane->old_fb) > drm_framebuffer_put(plane->old_fb); > plane->old_fb = NULL; > @@ -685,6 +682,7 @@ int drm_mode_setplane(struct drm_device *dev, void *data, > struct drm_plane *plane; > struct drm_crtc *crtc = NULL; > struct drm_framebuffer *fb = NULL; > + int ret; > > if (!drm_core_check_feature(dev, DRIVER_MODESET)) > return -EINVAL; > @@ -717,15 +715,16 @@ int drm_mode_setplane(struct drm_device *dev, void *data, > } > } > > - /* > - * setplane_internal will take care of deref'ing either the old or new > - * framebuffer depending on success. > - */ > - return setplane_internal(plane, crtc, fb, > - plane_req->crtc_x, plane_req->crtc_y, > - plane_req->crtc_w, plane_req->crtc_h, > - plane_req->src_x, plane_req->src_y, > - plane_req->src_w, plane_req->src_h); > + ret = setplane_internal(plane, crtc, fb, > + plane_req->crtc_x, plane_req->crtc_y, > + plane_req->crtc_w, plane_req->crtc_h, > + plane_req->src_x, plane_req->src_y, > + plane_req->src_w, plane_req->src_h); > + > + if (fb) > + drm_framebuffer_put(fb); > + > + return ret; > } > > static int drm_mode_cursor_universal(struct drm_crtc *crtc, > @@ -788,13 +787,12 @@ static int drm_mode_cursor_universal(struct drm_crtc *crtc, > src_h = fb->height << 16; > } > > - /* > - * setplane_internal will take care of deref'ing either the old or new > - * framebuffer depending on success. > - */ > ret = __setplane_internal(crtc->cursor, crtc, fb, > - crtc_x, crtc_y, crtc_w, crtc_h, > - 0, 0, src_w, src_h, ctx); > + crtc_x, crtc_y, crtc_w, crtc_h, > + 0, 0, src_w, src_h, ctx); > + > + if (fb) > + drm_framebuffer_put(fb); > > /* Update successful; save new cursor position, if necessary */ > if (ret == 0 && req->flags & DRM_MODE_CURSOR_MOVE) { > -- > 2.15.1 > > _______________________________________________ > 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
