Re: pata_it821x driver reports many FLUSH CACHE command failures

[Alan Cox]

On Thu, 23 Sep 2010 17:27:24 -0400
Chuck Ebbert <cebbert@xxxxxxxxxx> wrote:

> It looks like pata_it821x has never supported FLUSH_CACHE, but now

That depends on the firmware you have I believe

The ident it provides also doesn't advertise flush cache so something
appears to be issuing a cache flush despite the drive reporting that it
is not supported.

> we're seeing repeated failures. They happen over and over again and
> prevent installation. I stuck a dump_stack() in the failure path and
> got this:

Yes you'll crash some firmware versions if this occurs.

See:

static unsigned int it821x_read_id(struct ata_device *adev,
                                        struct ata_taskfile *tf, u16 *id)


If this has stopped working then you probably want to get Jeff to trace
back into the ATA and SCSI midlayer to see why it is issuing flushes for
a device which is reporting that cache flush is not supported - because
that is seriously broken.


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