Dne ponedeljek, 11. april 2022 ob 06:34:15 CEST je Samuel Holland napisal(a):
commit b4bdc4fbf8d0 ("soc: sunxi: Deal with the MBUS DMA offsets in a central place") added a platform device notifier that sets the DMA offset for all of the display engine frontend and backend devices.
The code applying the offset to DMA buffer physical addresses was then removed from the backend driver in commit 756668ba682e ("drm/sun4i: backend: Remove the MBUS quirks"), but the code subtracting PHYS_OFFSET was left in the frontend driver.
As a result, the offset was applied twice in the frontend driver. This likely went unnoticed because it only affects specific configurations (scaling or certain pixel formats) where the frontend is used, on boards with both one of these older SoCs and more than 1 GB of DRAM.
In addition, the references to PHYS_OFFSET prevent compiling the driver on architectures where PHYS_OFFSET is not defined.
Fixes: b4bdc4fbf8d0 ("soc: sunxi: Deal with the MBUS DMA offsets in a central
place")
Signed-off-by: Samuel Holland samuel@sholland.org
Good catch! Actually, people complained about non-working display on Cubietruck IIRC, which has 2 GB of RAM.
Did you test this on HW?
Reviewed-by: Jernej Skrabec jernej.skrabec@gmail.com
Best regards, Jernej
drivers/gpu/drm/sun4i/sun4i_frontend.c | 3 --- 1 file changed, 3 deletions(-)
diff --git a/drivers/gpu/drm/sun4i/sun4i_frontend.c b/drivers/gpu/drm/sun4i/
sun4i_frontend.c
index 56ae38389db0..462fae73eae9 100644 --- a/drivers/gpu/drm/sun4i/sun4i_frontend.c +++ b/drivers/gpu/drm/sun4i/sun4i_frontend.c @@ -222,13 +222,11 @@ void sun4i_frontend_update_buffer(struct sun4i_frontend
*frontend,
/* Set the physical address of the buffer in memory */ paddr = drm_fb_cma_get_gem_addr(fb, state, 0);
paddr -= PHYS_OFFSET; DRM_DEBUG_DRIVER("Setting buffer #0 address to %pad\n", &paddr); regmap_write(frontend->regs, SUN4I_FRONTEND_BUF_ADDR0_REG, paddr);
if (fb->format->num_planes > 1) { paddr = drm_fb_cma_get_gem_addr(fb, state, swap ? 2 :
1);
paddr -= PHYS_OFFSET;
&paddr);
regmap_write(frontend->regs,
SUN4I_FRONTEND_BUF_ADDR1_REG,
paddr);@@ -236,7 +234,6 @@ void sun4i_frontend_update_buffer(struct sun4i_frontend
*frontend,
if (fb->format->num_planes > 2) { paddr = drm_fb_cma_get_gem_addr(fb, state, swap ? 1 :
2);
paddr -= PHYS_OFFSET;
&paddr);
regmap_write(frontend->regs,
SUN4I_FRONTEND_BUF_ADDR2_REG,
paddr);-- 2.35.1