> -----Original Message----- > From: Paul Walmsley [mailto:paul@xxxxxxxxx] > Sent: Thursday, January 06, 2011 11:56 PM > To: Santosh Shilimkar > Cc: linux-omap@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > Subject: Re: [PATCH] omap: wd_timer: Fix crash frm wdt_probe when > !CONFIG_RUNTIME_PM > > Hi Santosh, > > On Wed, 5 Jan 2011, Santosh Shilimkar wrote: > > > Commit ff2516fb 'wd_timer: disable on boot via hwmod postsetup > mechanism' > > introduced watchdog timer state state management using > postsetup_state. > > This was done to allow some board files to support watchdog > coverage > > throughout kernel initialization and it work as intended when > RUNTIME_PM > > is enabled. > > > > With !CONFIG_RUNTIME_PM and no board is specifically requests > watchdog > > to remain enabled the omap_wdt_probe crashesh. This is because > hwmod > > in absense of runtime PM unable to turn watchdog clocks because > it's > > state is set to be disabled. For rest of the device, the state is > > set as enabled in absense of RUNTIME_PM > > > > [ 1.372558] Unhandled fault: imprecise external abort (0x1406) > at 0xad733eeb > > [ 1.379913] Internal error: : 1406 [#1] SMP > > [ 1.384277] last sysfs file: > > [ 1.387359] Modules linked in: > > [ 1.390563] CPU: 0 Tainted: G W (2.6.37-rc7-00265- > g4298a4c-dirty #23) > > [ 1.398468] PC is at omap_wdt_disable+0x2c/0x3c > > [ 1.403198] LR is at omap_wdt_probe+0x124/0x1e0 > > [ 1.407928] pc : [<c02f5bf4>] lr : [<c03be10c>] psr: > 60000013 > > [ 1.407958] sp : df833f00 ip : 00000000 fp : 00000000 > > [ 1.419921] r10: c0ac57ac r9 : df959e00 r8 : 00000000 > > [ 1.425384] r7 : df959e08 r6 : df8000c0 r5 : df95bebc r4 : > df87dde0 > > [ 1.432189] r3 : fc314000 r2 : 00005555 r1 : fc314034 r0 : > df87dde0 > > > > This patch make the default watchdog state to be enabled in case > of > > !CONFIG_RUNTIME_PM. This fixes the crash > > > > Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx> > > Cc: Paul Walmsley <paul@xxxxxxxxx> > > --- > > Paul, I am not too sure if it breaks your _shutdown idea of > watchdog > > timer. > > Maybe. What happens in a case where the bootloader enables the > watchdog, > but the booting kernel is compiled with !CONFIG_OMAP_WATCHDOG and > !CONFIG_PM_RUNTIME? Won't the watchdog reset the MPU unexpectedly > in that > case? Or am I missing something... > I had a same doubght. But the test I did with and without "CONFIG_OMAP_WATCHDOG" just at kernel level. The TI bootloader have MPU watchdog being always disabled. Will do a test on this scenario by explicitly disabling the MPU WDT in bootloader. Regards, Santosh -- 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
