On Wed, 2011-05-18 at 12:50 +0200, Kevin Hilman wrote: > Tomi Valkeinen <tomi.valkeinen@xxxxxx> writes: > > > Hi Kevin, > > > > I was fixing DSS context loss handling which is a bit broken, and while > > testing on OMAP3 Overo, with -rc7 and omap2plus_defconfig, I noticed > > that get_context_loss_count() seems to always return 0. > > > > 0 should be returned when an error happens, and as far as I see in > > pwrdm_get_context_loss_count(), no error is happening but the DSS > > context has just never been lost and the returned count is thus 0. > > > > Is this correct? And what happens when the count wraps and goes back to > > zero, does the function return 0 in that case? > > Hmm, you're right. zero is actually documented as the error return > value (even though it's not really checked.) > > Since driver's should only every care about the *difference* in value > between two calls to context_loss_count(), this might not be a big deal, > but a proper fix is probably to have the state counters start at one. But if there happens an error in get_context_loss_count(), for whatever reason, I'd guess it's safer from the driver's perspective to assume that a context restore _is_ needed. If the driver handles zero value as a normal return value, it would mean that the driver never restores context if get_context_loss_count() returns 0 for all calls. Tomi -- 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
