From mboxrd@z Thu Jan 1 00:00:00 1970 From: sshtylyov@mvista.com (Sergei Shtylyov) Date: Mon, 21 Mar 2011 16:42:05 +0300 Subject: [PATCH 18/20] video: msm: Prevent DMA lockups when switching bit depths In-Reply-To: <1300485585-27640-1-git-send-email-carlv@codeaurora.org> References: <1300484846-26393-1-git-send-email-carlv@codeaurora.org> <1300485585-27640-1-git-send-email-carlv@codeaurora.org> Message-ID: <4D8755AD.3060402@ru.mvista.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hello. Carl Vanderlip wrote: > 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. Maybe I'm blind again but I don't see any waiting... > Authors: > Dima Zavin > Rebecca Schultz Zavin > Colin Cross > Signed-off-by: Carl Vanderlip > --- > 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); WBR, Sergei