[PATCH 18/20] video: msm: Prevent DMA lockups when switching bit depths

From: Carl Vanderlip
Date: Fri Mar 18 2011 - 18:00:08 EST


Forces the lcdc off and waits a frame vsync period to prevent the MDP DMA
engine crashing if the DMA bit depth is changed. A sleep cannot be used
because lcdc_dma_start is called in irq context.

Authors:
Dima Zavin <dima@xxxxxxxxxxx>
Rebecca Schultz Zavin <rebecca@xxxxxxxxxxx>
Colin Cross <ccross@xxxxxxxxxxx>

Signed-off-by: Carl Vanderlip <carlv@xxxxxxxxxxxxxx>
---
drivers/video/msm/mdp.c | 7 +++++++
1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/drivers/video/msm/mdp.c b/drivers/video/msm/mdp.c
index b3f334ad..49d956a 100644
--- a/drivers/video/msm/mdp.c
+++ b/drivers/video/msm/mdp.c
@@ -564,6 +564,13 @@ void mdp_hw_init(struct mdp_info *mdp)
mdp_writel(mdp, 1, 0x60);
mdp_writel(mdp, 1, MDP_EBI2_PORTMAP_MODE);

+ /* disable lcdc */
+ mdp_writel(mdp, 0, MDP_LCDC_CTL);
+ /* enable auto clock gating for all blocks by default */
+ mdp_writel(mdp, 0xffffffff, MDP_CGC_EN);
+ /* reset color/gamma correct parms */
+ mdp_writel(mdp, 0, MDP_DMA_P_COLOR_CORRECT_CONFIG);
+
mdp_writel(mdp, 0, MDP_CMD_DEBUG_ACCESS_BASE + 0x01f8);
mdp_writel(mdp, 0, MDP_CMD_DEBUG_ACCESS_BASE + 0x01fc);
mdp_writel(mdp, 1, 0x60);
--
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

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