> -----Original Message----- > From: Ohad Ben-Cohen [mailto:ohad@xxxxxxxxxx] > Sent: Saturday, November 17, 2012 3:33 AM > To: Liu, Chuansheng > Cc: Chris Ball; linux-mmc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx > Subject: Re: [PATCH] mmc,sdio: Fix the panic due to devname NULL when > calling pm_runtime_set_active() > > Hi Liu, > > On Fri, Nov 16, 2012 at 2:54 PM, Chuansheng Liu > <chuansheng.liu@xxxxxxxxx> wrote: > > So when calling pm_runtime_set_active(), it will hit the strlen(devname==0) > > which trigger the panic. > > Can you please point to the exact line of code that triggers this panic ? The call trace is as below: mmc_rescan -> mmc_rescan_try_freq -> mmc_attach_sdio -> pm_runtime_set_active -> __pm_runtime_set_status -> __update_runtime_status -> trace_runtime_pm_status This function is corresponding to the below code in trace/events/power.h: TRACE_EVENT(runtime_pm_status, TP_PROTO(struct device *dev, int status), TP_ARGS(dev, status), TP_STRUCT__entry( __string(devname, dev_name(dev)) Rechecked these codes, the trace event runtime_pm_status is added newly, this is different with vanilla Linux. But it is just a new trace event. So I still think that calling pm_runtime_set_active is not safe when dev_name is NULL. If you agree this point, I can refine the code that moving "init the dev_name " from mmc_add_card to mmc_sdio_init_card. Thanks. > > > Here before calling pm_runtime_set_active(), set the dev name, although > > it is duplicated with mmc_add_card(), but it do not break the original > > design(commit 81968561b). > > Normally we'd like to avoid such a solution, so let's first make sure > we understand the problem. > > Have you tried thinking how come this shows up only now - has any of > the relevant code been changed lately ? Are you using a vanilla Linux > tree ? > > Thanks, > Ohad. -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
