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@xxxxxxxxxxxxx> wrote: > > On 10 November 2015 at 10:33, Daniel Kurtz <djkurtz@xxxxxxxxxxxx> 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@xxxxxxxxx> 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@xxxxxxxxx> --- 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); } /** -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
