Re: [PATCH v2 2/2] irqchip: Add Qualcomm MPM controller driver

[Maulik Shah]

Hi,

On 11/30/2021 2:01 PM, Shawn Guo wrote:
> >     This can be converted to read poll_timeout(). This was introduced in
> >     place of wmb() to make sure writes are completed.
> Hmm, in this case, writel() will just do the right thing, as it wraps
> wmb() there.  Or am I missing something?
>
> Shawn
#define writel(v,c)             ({ __iowmb(); writel_relaxed((v),(c)); })

writel() does not do wmb() after writel_relaxed(), it does before.

we need to make sure write is propagated, so wmb() or read  back with 
timeout need to be kept after writel() is done.

Thanks,
Maulik