On 01/18/2018 02:30 PM, Kevin Hao wrote:
From: Jyri Sarha <jsa...@ti.com>
commit ce99f7206c9105851d97202ed08c058af6f11ac4 upstream
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....@windriver.com>
Fixes: 11abbc9f39e0 ("drm/tilcdc: Set framebuffer DMA address to HW only if CRTC is
enabled")
Cc: <sta...@vger.kernel.org> # v4.11+
Signed-off-by: Jyri Sarha <jsa...@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkei...@ti.com>
---
This fixes the Bug 12131 - Kernel traceback when reboot beaglebone black.
https://bugzilla.yoctoproject.org/show_bug.cgi?id=12131
Thanks for adding this, it helps when considering the "why" for
a patch.
this is now merged, I'll do SRCREV updates in a bit, once some of
the recent CVE changes have been completed.
Bruce
drivers/gpu/drm/tilcdc/tilcdc_crtc.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
index d524ed0d5146..9e607b914c2b 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_reference(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)
@@ -636,7 +647,7 @@ 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)
--
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