Messages in this thread | | | Date | Tue, 30 Aug 2011 22:15:29 +0100 | From | Mark Brown <> | Subject | Re: [v2 3/4] platform: (TS-5500) add LED support |
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On Tue, Aug 30, 2011 at 05:14:24PM -0400, Vivien Didelot wrote: > "H. Peter Anvin" <hpa@zytor.com> wrote: > > On 08/29/2011 03:16 PM, Mark Brown wrote:
> > > Can you not do outb() from atomic context? The reason lots of LED > > > drivers update the hardware in a workqueue is that they communicate > > > with the hardware over buses that can't be used in atomic context > > > like I2C or SPI but if that's not an issue then the workqueue is > > > not required and the code can be simplified.
> > outb() can definitely be executed from atomic context.
> Good to know, thanks. I removed the work_struct and instead lock a mutex > before setting led->new_brightness and calling outb().
You can't take a mutex in atomic context...
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