[PATCH v3] drm: mediatek: change the variable type of rdma threshold

From: Bibby Hsieh
Date: Wed Jun 21 2017 - 22:43:51 EST


For some greater resolution, the rdma threshold
variable will overflow.

Signed-off-by: Bibby Hsieh <bibby.hsieh@xxxxxxxxxxxx>
---
drivers/gpu/drm/mediatek/mtk_disp_rdma.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
index 0df05f9..8540aaa 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_rdma.c
@@ -109,7 +109,7 @@ static void mtk_rdma_config(struct mtk_ddp_comp *comp, unsigned int width,
unsigned int height, unsigned int vrefresh,
unsigned int bpc)
{
- unsigned int threshold;
+ unsigned long long threshold;
unsigned int reg;

rdma_update_bits(comp, DISP_REG_RDMA_SIZE_CON_0, 0xfff, width);
@@ -121,10 +121,11 @@ static void mtk_rdma_config(struct mtk_ddp_comp *comp, unsigned int width,
* output threshold to 6 microseconds with 7/6 overhead to
* account for blanking, and with a pixel depth of 4 bytes:
*/
- threshold = width * height * vrefresh * 4 * 7 / 1000000;
+ threshold = div_u64((unsigned long long)width * height * vrefresh *
+ 4 * 7, 1000000);
reg = RDMA_FIFO_UNDERFLOW_EN |
RDMA_FIFO_PSEUDO_SIZE(SZ_8K) |
- RDMA_OUTPUT_VALID_FIFO_THRESHOLD(threshold);
+ RDMA_OUTPUT_VALID_FIFO_THRESHOLD(clamp_val(threshold, 0, 0x3ff0));
writel(reg, comp->regs + DISP_REG_RDMA_FIFO_CON);
}

--
1.9.1