Re: [PATCH] OMAPDSS: DISPC: set irq_safe for runtime PM
flat view
From: Rob Clark <hidden>
Date: 2013-09-19 15:14:58
On Thu, Sep 19, 2013 at 6:19 AM, Tomi Valkeinen [off-list ref] wrote:
We have a bug with omapdrm, where omapdrm calls dispc's pm_runtime function in atomic context, and dispc's pm_runtime is not marked as irq_safe: BUG: sleeping function called from invalid context at drivers/base/power/runtime.c:952 Dispc's runtime PM callbacks are irq safe, so we can just set the irq_safe flag to fix the issue. However, in the long term, I'd rather have omapdrm manage the runtime PM calls in a better way. Calling get/put for every small operation that touches the dispc registers is very inefficient. It'd be better and cleaner to have clear "in-use" and "not-in-use" states for dispc, so that we don't need to do register context restore for small operations, only to turn dispc off right afterwards.
hmm, quick mid-conference thought: in msm, in crtc->prepare and crtc->dpms(ON) I do clk_prepare_enable(), and inverse in commit()/dpms(OFF). (The extra ref held between prepare() and commit() avoids turning things off mid-modeset.) The net effect is that we hold things on when the display is on. Probably we should do something similar in omapdrm? BR, -R
quoted hunk ↗ jump to hunk
Signed-off-by: Tomi Valkeinen <redacted> --- drivers/video/omap2/dss/dispc.c | 1 + 1 file changed, 1 insertion(+)diff --git a/drivers/video/omap2/dss/dispc.c b/drivers/video/omap2/dss/dispc.c index 02a7340..4779750 100644 --- a/drivers/video/omap2/dss/dispc.c +++ b/drivers/video/omap2/dss/dispc.c@@ -3691,6 +3691,7 @@ static int __init omap_dispchw_probe(struct platform_device *pdev) } pm_runtime_enable(&pdev->dev); + pm_runtime_irq_safe(&pdev->dev); r = dispc_runtime_get(); if (r) --1.8.1.2