On Monday, January 11, 2016 12:35:28 PM Fabio Estevam wrote:
On Thu, Jan 7, 2016 at 12:47 PM, Tomeu Vizoso tomeu.vizoso@collabora.com wrote:
On 10 November 2015 at 10:33, Daniel Kurtz djkurtz@chromium.org wrote: [snip]
The problem appears to be that:
- On boot, platform_drv_probe() calls dev_pm_domain_attach() before
drv->probe(); thus, it calls dev_pm_domain_attach() while the device is unbound.
- However, for a platform_device, the reboot path calls
device_shutdown(), but not __device_release_driver(): device_shutdown() dev->driver->shutdown => platform_drv_shutdown() dev_pm_domain_detach() dev->pm_domain->detach() => genpd_dev_pm_detach() pm_genpd_remove_device() dev_pm_domain_set(dev, NULL);
So, for a platform_device in a genpd power domain with .shutdown installed, platform_drv_shutdown() calls dev_pm_domain_detach() while the device is still bound, which triggers the WARN().
Hi Rafael, Alan and Ulf,
do you have any suggestion about this? I don't really understand why the device is detached from the domain on shutdown.
I am running linux-next and this commit causes the same problem for me on a mx6 after running a 'reboot' command:
Requesting system reboot [ 15.058782] ------------[ cut here ]------------ [ 15.063459] WARNING: CPU: 3 PID: 1122 at drivers/base/power/common.c:150 dev_pm_domain_set+0x4c/0x58() [ 15.072838] PM domains can only be changed for unbound devices [ 15.078735] Modules linked in: [ 15.081849] CPU: 3 PID: 1122 Comm: init Not tainted 4.4.0-rc8-next-20160111-dirty #207 [ 15.089826] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) [ 15.096375] Backtrace: [ 15.098941] [<c00136d8>] (dump_backtrace) from [<c0013874>] (show_stack+0x18/0x1c) [ 15.106532] r6:00000096 r5:00000000 r4:00000000 r3:00000000 [ 15.112390] [<c001385c>] (show_stack) from [<c02de89c>] (dump_stack+0x88/0xa4) [ 15.119708] [<c02de814>] (dump_stack) from [<c002bcac>] (warn_slowpath_common+0x80/0xbc) [ 15.127860] r5:c03da810 r4:ee63bd68 [ 15.131533] [<c002bc2c>] (warn_slowpath_common) from [<c002bd8c>] (warn_slowpath_fmt+0x38/0x40) [ 15.140292] r8:eea01db0 r7:c0b0f87c r6:eea01d80 r5:00000000 r4:ef181410 [ 15.147165] [<c002bd58>] (warn_slowpath_fmt) from [<c03da810>] (dev_pm_domain_set+0x4c/0x58) [ 15.155661] r3:c0b0f7f0 r2:c09e82dc [ 15.159373] [<c03da7c4>] (dev_pm_domain_set) from [<c03e4e5c>] (genpd_free_dev_data+0x20/0x50) [ 15.168065] r5:ef1814a0 r4:ef181410 [ 15.171737] [<c03e4e3c>] (genpd_free_dev_data) from [<c03e5fe4>] (pm_genpd_remove_device+0xb4/0xe0) [ 15.180842] r6:ef181410 r5:eea01d80 r4:c0b0f7f0 r3:00000000 [ 15.186644] [<c03e5f30>] (pm_genpd_remove_device) from [<c03e6040>] (genpd_dev_pm_detach+0x30/0xac) [ 15.195743] r8:c0b0f7f0 r7:c1379734 r6:00000001 r5:c0b209c4 r4:ef181410 r3:00000000 [ 15.203694] [<c03e6010>] (genpd_dev_pm_detach) from [<c03da7c0>] (dev_pm_domain_detach+0x28/0x2c) [ 15.212621] r10:ef181444 r8:c0b6f560 r7:c1379734 r6:ef181410 r5:ef173c10 r4:ef181410 [ 15.220683] [<c03da798>] (dev_pm_domain_detach) from [<c03d3ea0>] (platform_drv_shutdown+0x34/0x38) [ 15.229817] [<c03d3e6c>] (platform_drv_shutdown) from [<c03d05b0>] (device_shutdown+0x3c/0x194)
OK, so does the appended patch help?
Rafael
--- From: Rafael J. Wysocki rafael.j.wysocki@intel.com Subject: [PATCH] platform: Do not detach from PM domains on shutdown
Shutdown is carried out when the driver is still bound to the device, so it is incorrect to detach it from a PM domain (if any) at this point.
Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com --- drivers/base/platform.c | 1 - 1 file changed, 1 deletion(-)
Index: linux-pm/drivers/base/platform.c =================================================================== --- linux-pm.orig/drivers/base/platform.c +++ linux-pm/drivers/base/platform.c @@ -577,7 +577,6 @@ static void platform_drv_shutdown(struct
if (drv->shutdown) drv->shutdown(dev); - dev_pm_domain_detach(_dev, true); }
/**