> -----Original Message----- > From: Kevin Hilman [mailto:khilman@xxxxxxxxxxxxxxxxxxx] > Sent: Friday, October 15, 2010 3:44 AM > To: Nayak, Rajendra > Cc: linux-omap@xxxxxxxxxxxxxxx; Paul Walmsley; Cousson, Benoit; Shilimkar, > Santosh > Subject: Re: [PATCH] OMAP: hmwod: Update the sysc_cache in case module > context is lost > > Rajendra Nayak <rnayak@xxxxxx> writes: > > > Do not skip the sysc programming in the hmwod framework based > > on the cached value alone, since at times the module might have lost > > context (due to the Powerdomain in which the module belongs > > transitions to either Open Switch RET or OFF). > > Shouldn't the driver for each IP be responsible for restoring it's > register contents after context loss, including it's SYSC? > > Seems to me that if SYSC is lost, it means the driver's save/restore > is buggy. > I am glad you asked this question. I had a same argument with Benoit that driver anyway does context save restore for other registers and it can do SYSC as well. But Benoit's point was that "sysconfig is a part of the PRCM located in the IP, but this is purely TI implementation specific. The same IP in another platform will not have this sysconfig entry. That's why its important to hide them from the driver " This make sense too. > > > Signed-off-by: Rajendra Nayak <rnayak@xxxxxx> > > Cc: Paul Walmsley <paul@xxxxxxxxx> > > Cc: Benoit Cousson <b-cousson@xxxxxx> > > Cc: Santosh Shilimkar <santosh.shilimkar@xxxxxx> > > Cc: Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx> > > --- > > arch/arm/mach-omap2/omap_hwmod.c | 5 ++++- > > 1 files changed, 4 insertions(+), 1 deletions(-) > > > > diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach- > omap2/omap_hwmod.c > > index cb911d7..e57fe21 100644 > > --- a/arch/arm/mach-omap2/omap_hwmod.c > > +++ b/arch/arm/mach-omap2/omap_hwmod.c > > @@ -115,7 +115,10 @@ static void _write_sysconfig(u32 v, struct > omap_hwmod *oh) > > > > /* XXX ensure module interface clock is up */ > > > > - if (oh->_sysc_cache != v) { > > + if ((oh->_sysc_cache != v) || > > + /* Did the module go to off and loose context? */ > > + (oh->_sysc_cache != > > + omap_hwmod_readl(oh, oh->class->sysc->sysc_offs))) { > > oh->_sysc_cache = v; > > omap_hwmod_writel(v, oh, oh->class->sysc->sysc_offs); > > } -- 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
