diff options
| author | Jyri Sarha <jsarha@ti.com> | 2017-10-12 12:19:46 +0300 |
|---|---|---|
| committer | Jyri Sarha <jsarha@ti.com> | 2017-10-13 15:24:21 +0300 |
| commit | ce99f7206c9105851d97202ed08c058af6f11ac4 (patch) | |
| tree | 61d725de2ecd5fc218deefc92d6ff510e049924b /drivers/gpu/drm/tilcdc | |
| parent | ba3fd954f0b4c2df1e0d7e243cb6735c6f4c5bdc (diff) | |
| download | linux-ce99f7206c9105851d97202ed08c058af6f11ac4.tar.xz | |
drm/tilcdc: Precalculate total frametime in tilcdc_crtc_set_mode()
We need the total frame refresh time to check if we are too close to
vertical sync when updating the two framebuffer DMA registers and risk
a collision. This new method is more accurate that the previous that
based on mode's vrefresh value, which itself is inaccurate or may not
even be initialized.
Reported-by: Kevin Hao <kexin.hao@windriver.com>
Fixes: 11abbc9f39e0 ("drm/tilcdc: Set framebuffer DMA address to HW only if CRTC is enabled")
Cc: <stable@vger.kernel.org> # v4.11+
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Diffstat (limited to 'drivers/gpu/drm/tilcdc')
| -rw-r--r-- | drivers/gpu/drm/tilcdc/tilcdc_crtc.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c index 704db2443b5e..6ef4d1a1e3a9 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c @@ -24,6 +24,7 @@ #include <linux/completion.h> #include <linux/dma-mapping.h> #include <linux/of_graph.h> +#include <linux/math64.h> #include "tilcdc_drv.h" #include "tilcdc_regs.h" @@ -48,6 +49,7 @@ struct tilcdc_crtc { unsigned int lcd_fck_rate; ktime_t last_vblank; + unsigned int hvtotal_us; struct drm_framebuffer *curr_fb; struct drm_framebuffer *next_fb; @@ -292,6 +294,12 @@ static void tilcdc_crtc_set_clk(struct drm_crtc *crtc) LCDC_V2_CORE_CLK_EN); } +uint tilcdc_mode_hvtotal(const struct drm_display_mode *mode) +{ + return (uint) div_u64(1000llu * mode->htotal * mode->vtotal, + mode->clock); +} + static void tilcdc_crtc_set_mode(struct drm_crtc *crtc) { struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc); @@ -459,6 +467,9 @@ static void tilcdc_crtc_set_mode(struct drm_crtc *crtc) drm_framebuffer_get(fb); crtc->hwmode = crtc->state->adjusted_mode; + + tilcdc_crtc->hvtotal_us = + tilcdc_mode_hvtotal(&crtc->hwmode); } static void tilcdc_crtc_enable(struct drm_crtc *crtc) @@ -642,7 +653,7 @@ int tilcdc_crtc_update_fb(struct drm_crtc *crtc, spin_lock_irqsave(&tilcdc_crtc->irq_lock, flags); next_vblank = ktime_add_us(tilcdc_crtc->last_vblank, - 1000000 / crtc->hwmode.vrefresh); + tilcdc_crtc->hvtotal_us); tdiff = ktime_to_us(ktime_sub(next_vblank, ktime_get())); if (tdiff < TILCDC_VBLANK_SAFETY_THRESHOLD_US) |