Mikael Pettersson wrote: > A Promise SATA controller will signal hotplug events when a hard > reset (COMRESET) is done on a port. These events aren't masked by > the driver, and the unexpected interrupts will cause a sequence > of failed reset attempts util libata's EH finally gives up. > > This has not been a common problem so far, but the pending libata > hardreset-by-default changes makes it a critical issue. > > The solution is to disable hotplug events before a reset, and to > reenable them afterwards. (Promise's driver does this too.) > > This patch adds SATA-specific versions of ->freeze() and ->thaw() > that also disable and enable hotplug events. PATA ports continue > to use the old versions of ->freeze() and ->thaw(). > > Accesses to the hotplug register must be serialised via host->lock. > We rely on ap->lock == &ap->host->lock and that libata takes this > lock before ->freeze() and ->thaw(). Document this requirement. > The interrupt handler is adjusted so its hotplug register accesses > are inside the region protected by host->lock. > > Tested on various chips (SATA300TX4, SATA300TX2plus, SATAII150TX4, > FastTrack TX4000) with various combinations of SATA and PATA disks, > with and without the pending hardreset-by-default changes. > > Signed-off-by: Mikael Pettersson <mikpe@xxxxxxxx> Acked-by: Tejun Heo <htejun@xxxxxxxxx> Jeff, do you want to merge this first? If so, I'll update the prefer-hardreset and cleanup-sht-ops patchsets; otherwise, I'll massage this patch a bit so that it fits on top of those two patchsets. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
