[PATCH 6/7] ARM: OMAP2+: Improve omap_device error for driver writers
From: Ulf Hansson <hidden>
Date: 2016-02-12 12:53:34
Also in:
linux-i2c, linux-mmc, linux-omap, linux-serial, linux-spi
On 11 February 2016 at 00:02, Tony Lindgren [off-list ref] wrote:
Drivers using pm_runtime_use_autosuspend() may not get disabled after -EPROBE_DEFER. On the following device driver probe, hardware state is different from the PM runtime state causing omap_device to produce the following error: omap_device_enable() called from invalid state 1 And with omap_device and omap hardware being picky for PM, this will block any deeper idle states in hardware. Let's add a proper error message so driver writers can easily fix their drivers for PM. In general, the solution is to fix the drivers to follow the PM runtime documentation: 1. For sections of code that needs the device disabled, use pm_runtime_put_sync_suspend() if pm_runtime_set_autosuspend() has been set. 2. For driver exit code, use pm_runtime_dont_use_autosuspend() before pm_runtime_put_sync() if pm_runtime_use_autosuspend() has been set. Let's not return with 0 from _od_runtime_resume() as that will eventually lead into new drivers with broken PM runtime that will block deeper idle states on omaps. Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Nishanth Menon <nm@ti.com> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Ulf Hansson <redacted> Cc: Tero Kristo <redacted> Signed-off-by: Tony Lindgren <tony@atomide.com>
Acked-by: Ulf Hansson <redacted> Kind regards Uffe
quoted hunk ↗ jump to hunk
--- arch/arm/mach-omap2/omap_device.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)diff --git a/arch/arm/mach-omap2/omap_device.c b/arch/arm/mach-omap2/omap_device.c index 0437537..ebd8369 100644 --- a/arch/arm/mach-omap2/omap_device.c +++ b/arch/arm/mach-omap2/omap_device.c@@ -602,8 +602,10 @@ static int _od_runtime_resume(struct device *dev) int ret; ret = omap_device_enable(pdev); - if (ret) + if (ret) { + dev_err(dev, "use pm_runtime_put_sync_suspend() in driver?\n"); return ret; + } return pm_generic_runtime_resume(dev); } --2.7.0