From f36eb5a899d3ea57e3d167427260848e116e27a0 Mon Sep 17 00:00:00 2001 From: Tomi Valkeinen Date: Wed, 3 Sep 2014 19:25:54 +0000 Subject: [PATCH] drm/omap: add pin refcounting to omap_framebuffer omap_framebuffer_pin() and omap_framebuffer_unpin() are currently broken, as they cannot be called multiple times (i.e. pin, pin, unpin, unpin), which is what happens in certain cases. This issue causes the driver to possibly use 0 as an address for a displayed buffer, leading to OCP error from DSS. This patch fixes the issue by adding a simple pin_count, used to track the number of pins. Signed-off-by: Tomi Valkeinen --- drivers/gpu/drm/omapdrm/omap_fb.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/gpu/drm/omapdrm/omap_fb.c b/drivers/gpu/drm/omapdrm/omap_fb.c index 45dd9eed9c57..d1e5f6da30d4 100644 --- a/drivers/gpu/drm/omapdrm/omap_fb.c +++ b/drivers/gpu/drm/omapdrm/omap_fb.c @@ -86,6 +86,7 @@ struct plane { struct omap_framebuffer { struct drm_framebuffer base; + int pin_count; const struct format *format; struct plane planes[4]; }; @@ -249,6 +250,11 @@ int omap_framebuffer_pin(struct drm_framebuffer *fb) struct omap_framebuffer *omap_fb = to_omap_framebuffer(fb); int ret, i, n = drm_format_num_planes(fb->pixel_format); + if (omap_fb->pin_count > 0) { + omap_fb->pin_count++; + return 0; + } + for (i = 0; i < n; i++) { struct plane *plane = &omap_fb->planes[i]; ret = omap_gem_get_paddr(plane->bo, &plane->paddr, true); @@ -257,6 +263,8 @@ int omap_framebuffer_pin(struct drm_framebuffer *fb) omap_gem_dma_sync(plane->bo, DMA_TO_DEVICE); } + omap_fb->pin_count++; + return 0; fail: @@ -275,6 +283,11 @@ int omap_framebuffer_unpin(struct drm_framebuffer *fb) struct omap_framebuffer *omap_fb = to_omap_framebuffer(fb); int ret, i, n = drm_format_num_planes(fb->pixel_format); + omap_fb->pin_count--; + + if (omap_fb->pin_count > 0) + return 0; + for (i = 0; i < n; i++) { struct plane *plane = &omap_fb->planes[i]; ret = omap_gem_put_paddr(plane->bo);