Messages in this thread | | | Date | Mon, 24 Mar 2008 22:31:55 -0400 | From | Jeff Garzik <> | Subject | Re: [PATCH 2.6.25-rc6] sata_promise: fix hardreset hotplug events, take 2 |
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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@it.uu.se> > --- > Changes since previous version: > - rephrase the problem description to avoid calling it a HW quirk, > the behaviour is apparently standard > - fix double locking bug found by Tejun, now tested with SMP kernel > - document locking rules for the global hotplug register > - inline the hotplug enable/disable code in freeze/thaw > > drivers/ata/sata_promise.c | 109 ++++++++++++++++++++++++++++++++++++--------- > 1 file changed, 88 insertions(+), 21 deletions(-)
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