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| author | Jyri Sarha <jsarha@ti.com> | 2016-08-26 15:10:14 +0300 |
|---|---|---|
| committer | Jyri Sarha <jsarha@ti.com> | 2016-09-01 22:31:59 +0300 |
| commit | 7eb9f069ff5dd39d44d7ecdf63eb99b429c7dad0 (patch) | |
| tree | 7e19fda5f1a9830b3ce48117a3793832fd2565f8 /drivers/gpu/drm/tilcdc/tilcdc_crtc.c | |
| parent | 63b07a8d8177675c5a4297de477fd511e9be7896 (diff) | |
| download | lwn-7eb9f069ff5dd39d44d7ecdf63eb99b429c7dad0.tar.gz lwn-7eb9f069ff5dd39d44d7ecdf63eb99b429c7dad0.zip | |
drm/tilcdc: Write DMA base and ceiling address with single instruction
Write DMA base and ceiling address with a single instruction, if
available. This should make it more unlikely that LCDC would fetch the
DMA addresses in the middle of an update. Having bad combination of
addresses in dma base and ceiling (e.g base > ceiling) can cause
unpredictaple behavior in LCDC.
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Diffstat (limited to 'drivers/gpu/drm/tilcdc/tilcdc_crtc.c')
| -rw-r--r-- | drivers/gpu/drm/tilcdc/tilcdc_crtc.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c index 163f111cd481..208768922030 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c @@ -69,6 +69,7 @@ static void set_scanout(struct drm_crtc *crtc, struct drm_framebuffer *fb) struct drm_gem_cma_object *gem; unsigned int depth, bpp; dma_addr_t start, end; + u64 dma_base_and_ceiling; drm_fb_get_bpp_depth(fb->pixel_format, &depth, &bpp); gem = drm_fb_cma_get_gem_obj(fb, 0); @@ -79,8 +80,13 @@ static void set_scanout(struct drm_crtc *crtc, struct drm_framebuffer *fb) end = start + (crtc->mode.vdisplay * fb->pitches[0]); - tilcdc_write(dev, LCDC_DMA_FB_BASE_ADDR_0_REG, start); - tilcdc_write(dev, LCDC_DMA_FB_CEILING_ADDR_0_REG, end - 1); + /* Write LCDC_DMA_FB_BASE_ADDR_0_REG and LCDC_DMA_FB_CEILING_ADDR_0_REG + * with a single insruction, if available. This should make it more + * unlikely that LCDC would fetch the DMA addresses in the middle of + * an update. + */ + dma_base_and_ceiling = (u64)(end - 1) << 32 | start; + tilcdc_write64(dev, LCDC_DMA_FB_BASE_ADDR_0_REG, dma_base_and_ceiling); if (tilcdc_crtc->curr_fb) drm_flip_work_queue(&tilcdc_crtc->unref_work, |