On Mon, 13 Oct 2008 14:16:24 +0900, Tejun Heo wrote: >Mikael Pettersson wrote: >> - hardreset in sata_promise seems broken. I'll take a closer look >> at that in about a week's time (I'll be busy with other work the >> next couple of days). > >This looks like a rather serious problem, so please take a look at >this. I've done more tests now, and the problem is that errors detected outside of sata_promise itself, typically timeouts, don't trigger the pdc_reset_port() call needed to bring the ATA engine behind the port back to sanity. And the reason no Promise-specific reset is done on timeouts is that libata-eh freezes the port before calling ->error_handler. sata_promise's error_handler only does a reset if the port is non-frozen, and I think that's because we don't want to destroy error status bits needed by EH autopsy. The solution I've been testing is the straightforward one of overriding ->prereset with code which calls pdc_reset_port() before calling the default prereset. (See patch below.) (Promise's own driver issues resets whenever there's a sign of a problem.) One of my test disks will often trigger a timeout if smartctl accesses it when it's spun down. Previously the port would not recover from that, but now it's just a brief reset/detect and then it's up again. /Mikael --- linux-2.6.27/drivers/ata/sata_promise.c.~1~ 2008-07-14 10:22:36.000000000 +0200 +++ linux-2.6.27/drivers/ata/sata_promise.c 2008-10-20 00:20:58.000000000 +0200 @@ -153,6 +153,7 @@ static void pdc_freeze(struct ata_port * static void pdc_sata_freeze(struct ata_port *ap); static void pdc_thaw(struct ata_port *ap); static void pdc_sata_thaw(struct ata_port *ap); +static int pdc_prereset(struct ata_link *link, unsigned long deadline); static void pdc_error_handler(struct ata_port *ap); static void pdc_post_internal_cmd(struct ata_queued_cmd *qc); static int pdc_pata_cable_detect(struct ata_port *ap); @@ -175,6 +176,7 @@ static const struct ata_port_operations .sff_irq_clear = pdc_irq_clear, .post_internal_cmd = pdc_post_internal_cmd, + .prereset = pdc_prereset, .error_handler = pdc_error_handler, }; @@ -691,6 +693,12 @@ static void pdc_sata_thaw(struct ata_por readl(host_mmio + hotplug_offset); /* flush */ } +static int pdc_prereset(struct ata_link *link, unsigned long deadline) +{ + pdc_reset_port(link->ap); + return ata_sff_prereset(link, deadline); +} + static void pdc_error_handler(struct ata_port *ap) { if (!(ap->pflags & ATA_PFLAG_FROZEN)) -- 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