Re: [PATCH 2.6.19 2/3] sata_promise: new EH conversion

From: Jeff Garzik
Date: Wed Dec 06 2006 - 04:14:07 EST


Mikael Pettersson wrote:
On Sun, 03 Dec 2006 22:00:42 +0900, Tejun Heo wrote:
Mikael Pettersson wrote:
+}
+
+static void pdc_error_handler(struct ata_port *ap)
+{
+ struct ata_eh_context *ehc = &ap->eh_context;
+ ata_reset_fn_t hardreset;
+
+ /* stop DMA, mask IRQ, don't clobber anything else */
+ ata_eh_freeze_port(ap);
Don't freeze port unconditionally. You'll end up hardresetting on every
error. Just make sure DMA engine is stopped and the controller is in a
sane state. If that fails, then, the port should be frozen.

I'm looking into this now, but so far it seems only a reset
(what Promise calls software reset, I don't know if libata
considers it a soft or hard reset) of the ATA channel will do.

+ hardreset = NULL;
+ if (sata_scr_valid(ap)) {
+ ehc->i.action |= ATA_EH_HARDRESET;
Why always force HARDRESET?

I based that on sata_sil24:

if (sil24_init_port(ap)) {
ata_eh_freeze_port(ap);
ehc->i.action |= ATA_EH_HARDRESET;
}

I interpreted the ATA_EH_HARDRESET as being required due to
the ata_eh_freeze_port(), but perhaps it's only there because
sil24_init_port() returned failure?

A different issue, but of practical importance, is which
libata branch I should base the EH conversion on: #upstream
or #ALL? Andrew Morton's -mm kernels include the ALL patches,
but they in turn include the promise-sata-pata patches, and
there is a conflict between the PATA patch and the EH conversion.
Currently my EH conversion is based on #upstream, and I've ported
the PATA patch to apply on top of it.

It's a tiered system ;-)

* if at all possible, provide patches against the latest linux-2.6.git

* if there are dependencies in #upstream-fixes or #upstream (i.e. I already applied some of your patches), provide patches against #upstream-fixes or #upstream

#ALL is a branch that is blown away at will, and is really more of a testing and akpm sync point. Don't worry about conflicts with promise-sata-pata, I take care of those when I merge the #ALL branch together.

Jeff



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