On Tue, Mar 13, 2012 at 10:01 PM, Kevin Hilman <khilman@xxxxxx> wrote: > Santosh Shilimkar <santosh.shilimkar@xxxxxx> writes: > >> On Monday 12 March 2012 10:21 PM, Kevin Hilman wrote: >>> Santosh Shilimkar <santosh.shilimkar@xxxxxx> writes: >>> >>>> On OMAP4, recently a synchronisation bug is discovered by hardware >>>> team, which leads to incorrect timer value read from 32K sync timer >>>> IP when the IP is comming out of idle. >>>> >>>> The issue is due to the synchronization methodology used in the SYNCTIMER IP. >>>> The value of the counter register in 32kHz domain is synchronized to the OCP >>>> domain register only at count up event, and if the OCP clock is switched off, >>>> the OCP register gets out of synch until the first count up event after the >>>> clock is switched back -at the next falling edge of the 32kHz clock. >>>> >>>> Further investigation revealed that it applies to gptimer1 and watchdog timer2 >>>> as well which may run on 32KHz. This patch fixes the issue for all the >>>> applicable modules. >>> >>> The changelog describes the problem ver well, but doesn't actually >>> describe the fix (enable static dep.) Can you update the changelog do >>> describe the fix, and why it fixes the problem. >>> >> Sure. Updated patch below. The idea is to ensure that synctimer is >> syncronised before software does any reads on the counter. The BUG >> will get fixed in future OMAP designs > > Thanks for the updated changelog. > > Since this doesn't qualify as a regression, queuing for v3.4 (branch: for_3.4/fixes/pm) > Thanks Kevin. 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
