iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

drm/tilcdc: Precalculate total frametime in tilcdc_crtc_set_mode()

Browse Source 
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.hao@windriver.com>
Fixes: 11abbc9f39e0 ("drm/tilcdc: Set framebuffer DMA address to HW only if CRTC is enabled")
Signed-off-by: Jyri Sarha <jsarha@ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jyri Sarha 2017-10-12 12:19:46 +03:00 committed by Greg Kroah-Hartman
parent a5851fdb17
commit e3c5870862
1 changed files with 12 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
drivers/gpu/drm/tilcdc/tilcdc_crtc.c
View File

@ -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)
@ -648,7 +659,7 @@ 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)