From: Jae Hyun Yoo jae.hyun.yoo@linux.intel.com
[ Upstream commit 3536169f8531c2c5b153921dc7d1ac9fd570cda7 ]
Video engine uses eclk and vclk for its clock sources and its reset control is coupled with eclk so the current clock enabling sequence works like below.
Enable eclk De-assert Video Engine reset 10ms delay Enable vclk
It introduces improper reset on the Video Engine hardware and eventually the hardware generates unexpected DMA memory transfers that can corrupt memory region in random and sporadic patterns. This issue is observed very rarely on some specific AST2500 SoCs but it causes a critical kernel panic with making a various shape of signature so it's extremely hard to debug. Moreover, the issue is observed even when the video engine is not actively used because udevd turns on the video engine hardware for a short time to make a query in every boot.
To fix this issue, this commit changes the clock handling logic to make the reset de-assertion triggered after enabling both eclk and vclk. Also, it adds clk_unprepare call for a case when probe fails.
clk: ast2600: fix reset settings for eclk and vclk Video engine reset setting should be coupled with eclk to match it with the setting for previous Aspeed SoCs which is defined in clk-aspeed.c since all Aspeed SoCs are sharing a single video engine driver. Also, reset bit 6 is defined as 'Video Engine' reset in datasheet so it should be de-asserted when eclk is enabled. This commit fixes the setting.
Fixes: d2b4387f3bdf ("media: platform: Add Aspeed Video Engine driver") Signed-off-by: Jae Hyun Yoo jae.hyun.yoo@linux.intel.com Reviewed-by: Joel Stanley joel@jms.id.au Reviewed-by: Eddie James eajames@linux.ibm.com Fixes: d3d04f6c330a ("clk: Add support for AST2600 SoC") Reviewed-by: Joel Stanley joel@jms.id.au Acked-by: Stephen Boyd sboyd@kernel.org Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Signed-off-by: Mauro Carvalho Chehab mchehab+huawei@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/clk/clk-ast2600.c | 4 ++-- drivers/media/platform/aspeed-video.c | 9 ++++++--- 2 files changed, 8 insertions(+), 5 deletions(-)
diff --git a/drivers/clk/clk-ast2600.c b/drivers/clk/clk-ast2600.c index 84ca38450d02..af957179b135 100644 --- a/drivers/clk/clk-ast2600.c +++ b/drivers/clk/clk-ast2600.c @@ -58,10 +58,10 @@ static void __iomem *scu_g6_base; static const struct aspeed_gate_data aspeed_g6_gates[] = { /* clk rst name parent flags */ [ASPEED_CLK_GATE_MCLK] = { 0, -1, "mclk-gate", "mpll", CLK_IS_CRITICAL }, /* SDRAM */ - [ASPEED_CLK_GATE_ECLK] = { 1, -1, "eclk-gate", "eclk", 0 }, /* Video Engine */ + [ASPEED_CLK_GATE_ECLK] = { 1, 6, "eclk-gate", "eclk", 0 }, /* Video Engine */ [ASPEED_CLK_GATE_GCLK] = { 2, 7, "gclk-gate", NULL, 0 }, /* 2D engine */ /* vclk parent - dclk/d1clk/hclk/mclk */ - [ASPEED_CLK_GATE_VCLK] = { 3, 6, "vclk-gate", NULL, 0 }, /* Video Capture */ + [ASPEED_CLK_GATE_VCLK] = { 3, -1, "vclk-gate", NULL, 0 }, /* Video Capture */ [ASPEED_CLK_GATE_BCLK] = { 4, 8, "bclk-gate", "bclk", 0 }, /* PCIe/PCI */ /* From dpll */ [ASPEED_CLK_GATE_DCLK] = { 5, -1, "dclk-gate", NULL, CLK_IS_CRITICAL }, /* DAC */ diff --git a/drivers/media/platform/aspeed-video.c b/drivers/media/platform/aspeed-video.c index e0299a789923..6dde49d9aa4c 100644 --- a/drivers/media/platform/aspeed-video.c +++ b/drivers/media/platform/aspeed-video.c @@ -491,8 +491,8 @@ static void aspeed_video_off(struct aspeed_video *video) aspeed_video_write(video, VE_INTERRUPT_STATUS, 0xffffffff);
/* Turn off the relevant clocks */ - clk_disable(video->vclk); clk_disable(video->eclk); + clk_disable(video->vclk);
clear_bit(VIDEO_CLOCKS_ON, &video->flags); } @@ -503,8 +503,8 @@ static void aspeed_video_on(struct aspeed_video *video) return;
/* Turn on the relevant clocks */ - clk_enable(video->eclk); clk_enable(video->vclk); + clk_enable(video->eclk);
set_bit(VIDEO_CLOCKS_ON, &video->flags); } @@ -1684,8 +1684,11 @@ static int aspeed_video_probe(struct platform_device *pdev) return rc;
rc = aspeed_video_setup_video(video); - if (rc) + if (rc) { + clk_unprepare(video->vclk); + clk_unprepare(video->eclk); return rc; + }
return 0; }