Re: [PATCH] Revert "ata: sata_mv: Convert to devm_ioremap_resource()"

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Wed, 2017-05-24 at 15:01 +0200, Gregory CLEMENT wrote:
> Hi Andrew,
>  
>  On mer., mai 24 2017, Andrew Lunn <andrew@lunn.ch> wrote:
> 
> > This reverts commit 368e5fbdfc60732643f34f538823ed4bc8829827.
> > 
> > devm_ioremap_resource() enforces that there are no overlapping
> > resources, where as devm_ioremap() does not. The sata phy driver
> > needs
> > a subset of the sata IO address space, so maps some of the sata
> > address space. As a result, sata_mv now fails to probe, reporting it
> > cannot get its resources, and so we don't have any SATA disks.
> > 
> > Signed-off-by: Andrew Lunn <andrew@lunn.ch>
> 
> For this patch as it fixes a regresssion:
> 
> Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
> 
> However, as the same set of register are accessed by two drivers, is
> there a risk for a race condition ?
> 
> In this case we may consider to use a regmap.
> 
> Or maybe they never aces the same register ?

I'm wondering where exactly first resource acquiring is happening.

For me seems that the initial patch unhides the issue.

> 
> In this case it is safe to let the driver as is, but adding a comment
> could be useful.


-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy