On Fri, Mar 30, 2012 at 1:37 PM, Tomi Valkeinen <[email protected]> wrote: > Hi, > > I just found out about OMAP4 errata i740: > > DESCRIPTION > A bug has been identified in the interconnect agent handling the > connect-disconnect protocol between an > initiator and interconnect. When the disconnect protocol violation occurs, > there is a dead lock and a > system lockup is observed. > > The issue can occur in a corner case when the impacted module has started a > transition to standby, for > the L3 initiator on which it is attached, exactly at the time the initiator > gets an event for exiting idle state. > Such a situation can occur when the impacted initiator is generating short > MStandby pulses (pulse > durations less than one L4 clock cycle). > > DSS and ISS are the only initiators that are impacted. > > WORKAROUND > L3_CLK1 must be kept in NO-IDLE when the DSS clock domain is ON. It can be > switched back to > HW_AUTO when the DSS clock domain is IDLE. > > L3_CLK2 must be kept in NO-IDLE when the ISS clock domain is ON. It can be > switched back to > HW_AUTO when the ISS clock domain is IDLE. > > > All OMAP4 versions seem to be affected. I couldn't find a mention about > this in the mainline kernel. Any ideas how and where this should be > fixed? > It's not patched for mainline. Generally clock-domain code is abstracted from drivers but considering the errata and affected modules, I guees it should be handled by DSS driver since that is where the state of DSS or ISS will be known. Note ISS will be automatically taken care since it will always use disaplay.
In internal tree's this was handled as part of DSS early suspend/resume Regards Santosh -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
