From: Janusz Krzysztofik Date: Wed, 11 Nov 2009 19:00:03 +0000 (-0800) Subject: omap: Fix omapfb/lcdc on OMAP1510 broken when PM set X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=8561a84f85eccddf46212622f1f18317a220891b;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git omap: Fix omapfb/lcdc on OMAP1510 broken when PM set With CONFIG_PM=y, the omapfb/lcdc device on Amstrad Delta, after initially starting correctly, breaks with the following error messages: omapfb omapfb: resetting (status 0xffffff96,reset count 1) ... omapfb omapfb: resetting (status 0xffffff96,reset count 100) omapfb omapfb: too many reset attempts, giving up. Looking closer at this I have found that it had been broken almost 2 years ago with commit 2418996e3b100114edb2ae110d5d4acb928909d2, PM fixes for OMAP1. The definite reason for broken omapfb/lcdc behavoiur in PM mode appeared to be ARM_IDLECT1:IDLIF_ARM (bit 6) put into idle regardless of LCD DMA possibly running. The bit were set based on return value of the omap_dma_running() function that did not check for dedicated LCD DMA channel status. The patch below fixes this. Note that the hardcoded register value will be fixed during the next merge cycle to use OMAP_LCDC_ defines. Currently the OMAP_LCDC_ defines are local to drivers/video/omap/lcdc.c, so let's not start moving those right now. Created against linux-2.6.32-rc6 Tested on Amstrad Delta Signed-off-by: Janusz Krzysztofik Signed-off-by: Tony Lindgren --- diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c index 02ed94526aa3..68eaae324b6a 100644 --- a/arch/arm/plat-omap/dma.c +++ b/arch/arm/plat-omap/dma.c @@ -1114,6 +1114,14 @@ int omap_dma_running(void) { int lch; + /* + * On OMAP1510, internal LCD controller will start the transfer + * when it gets enabled, so assume DMA running if LCD enabled. + */ + if (cpu_is_omap1510()) + if (omap_readw(0xfffec000 + 0x00) & (1 << 0)) + return 1; + /* Check if LCD DMA is running */ if (cpu_is_omap16xx()) if (omap_readw(OMAP1610_DMA_LCD_CCR) & OMAP_DMA_CCR_EN)