Re: [PATCH V3 2/4] AC97 driver for mpc5200
From: Grant Likely <hidden>
Date: 2009-05-25 16:01:18
Also in:
alsa-devel
From: Grant Likely <hidden>
Date: 2009-05-25 16:01:18
Also in:
alsa-devel
On Mon, May 25, 2009 at 9:21 AM, Jon Smirl [off-list ref] wrote:
On Mon, May 25, 2009 at 6:26 AM, Mark Brown [off-list ref] wrote:quoted
quoted
+ =A0 =A0 =A0 =A0 =A0 =A0 spin_lock(&psc_dma->lock); + =A0 =A0 =A0 =A0 =A0 =A0 out_be32(&psc_dma->psc_regs->ac97_slots, psc_=
dma->slots);
quoted
quoted
+ =A0 =A0 =A0 =A0 =A0 =A0 spin_unlock(&psc_dma->lock); + =A0 =A0 =A0 =A0 =A0 =A0 break;This locking looks wrong - I'd expect it to also cover the modification of psc_dma->slots? =A0Otherwise it's hard to see what it buys you.Grant, why are you spin locking around register access?
This lock/unlock is definitely bogus since a single register access is already atomic. Are there places in the code that I wrote where a spin_lock/unlock is done around a single register access? g. --=20 Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd.