Re: [PATCH 4/4] ata: libata-core: do not retry reading the log on timeout

[Niklas Cassel <Niklas.Cassel@wdc.com>]

On Sat, Oct 08, 2022 at 01:47:49AM +0200, Niklas Cassel wrote:
> On Sat, Oct 08, 2022 at 07:33:54AM +0900, Damien Le Moal wrote:
> > On 10/7/22 22:23, Niklas Cassel wrote:
> > > ata_read_log_page() first tries to read the log using READ LOG DMA EXT.
> > > If that fails it will instead try to read the log using READ LOG EXT.
> > > 
> > > ata_exec_internal_sg() is synchronous, so it will wait for the command to
> > > finish. If we actually got an error back from the device, it is correct
> > > to retry. However, if the command timed out, ata_exec_internal_sg() will
> > > freeze the port.
> > > 
> > > There is no point in retrying if the port is frozen, as
> > > ata_exec_internal_sg() will return AC_ERR_SYSTEM on a frozen port,
> > > without ever sending the command down to the drive.
> > > 
> > > Therefore, avoid retrying if the first command froze the port, as that
> > > will result in a misleading AC_ERR_SYSTEM error print, instead of printing
> > > the error that actually caused the port to be frozen (AC_ERR_TIMEOUT).
> > 
> > Beside ata_read_log_page(), are there any other path that do a retry after
> > ata_exec_internal_sg() fails ?
> 
> Let me check and get back to you.

Hello Damien,

I couldn't find any other caller of ata_exec_internal_sg() or
ata_exec_internal() where this should be needed.


Kind regards,
Niklas