github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-09-24 06:24:02 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

drm: lcdif: Set undocumented bit to clear FIFO at vsync

Browse Source 
There is an undocumented bit used in the NXP BSP to clear the FIFO
systematically at vsync. In normal operation, the FIFO should already
be empty but it doesn't hurt to add it as an extra safety measure.

Signed-off-by: Paul Kocialkowski <paulk@sys-base.io>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reviewed-by: Liu Ying <victor.liu@nxp.com>
Link: https://patch.msgid.link/20260402183351.3281123-2-paulk@sys-base.io
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
This commit is contained in:
Paul Kocialkowski 2026-04-02 20:33:50 +02:00 committed by Lucas Stach
parent 3764568dd2
commit 108b5876d6
2 changed files with 3 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
drivers/gpu/drm/mxsfb/lcdif_kms.c
View File

@ -338,7 +338,8 @@ static void lcdif_set_mode(struct lcdif_drm_private *lcdif, u32 bus_flags)
* Downstream set it to 256B burst size to improve the memory
* efficiency so set it here too.
*/
ctrl = CTRLDESCL0_3_P_SIZE(2) | CTRLDESCL0_3_T_SIZE(2) |
ctrl = CTRLDESCL0_3_STATE_CLEAR_VSYNC |
CTRLDESCL0_3_P_SIZE(2) | CTRLDESCL0_3_T_SIZE(2) |
CTRLDESCL0_3_PITCH(lcdif->crtc.primary->state->fb->pitches[0]);
writel(ctrl, lcdif->base + LCDC_V8_CTRLDESCL0_3);
}

1
drivers/gpu/drm/mxsfb/lcdif_regs.h
View File

@ -190,6 +190,7 @@
#define CTRLDESCL0_1_WIDTH(n) ((n) & 0xffff)
#define CTRLDESCL0_1_WIDTH_MASK GENMASK(15, 0)
#define CTRLDESCL0_3_STATE_CLEAR_VSYNC BIT(23)
#define CTRLDESCL0_3_P_SIZE(n) (((n) << 20) & CTRLDESCL0_3_P_SIZE_MASK)
#define CTRLDESCL0_3_P_SIZE_MASK GENMASK(22, 20)
#define CTRLDESCL0_3_T_SIZE(n) (((n) << 16) & CTRLDESCL0_3_T_SIZE_MASK)