[PATCH 04/10] sata: hardreset: retry if phys link is down

Tejun Heo tj at kernel.org
Sun Jan 15 15:10:49 PST 2017


On Fri, Jan 13, 2017 at 01:37:58PM +0100, Bartosz Golaszewski wrote:
> The sata core driver already retries to resume the link because some
> controllers ignore writes to the SControl register.
> We have a use case with the da850 SATA controller where at PLL0
> frequency of 456MHz (needed to properly service the LCD controller)
> the chip becomes unstable and the hardreset operation is ignored the
> first time 50% of times.
> Retrying just the resume operation doesn't work - we need to issue
> the phy/wake reset again to make it work.
> If ata_phys_link_offline() returns true in sata_link_hardreset(),
> retry a couple times before really giving up.

I think it'd be better to implement the driver specific implementation
rather than changing the behavior for everybody.



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