Messages in this thread | | | Date | Tue, 30 Aug 2011 14:39:28 -0400 | From | Vivien Didelot <> | Subject | Re: [v2 2/4] platform: (TS-5500) add GPIO support |
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On Mon, 29 Aug 2011 23:11:33 +0100, Mark Brown <broonie@opensource.wolfsonmicro.com> wrote: > On Fri, Aug 26, 2011 at 07:40:25PM -0400, Vivien Didelot wrote: > > + bitno = line_to_bit_map[offset]; > > + > > + mutex_lock(&drvdata->gpio_lock); > > + byte = inb(ioaddr); > > + mutex_unlock(&drvdata->gpio_lock); > > Do you really need the lock to do a read?
Is there any chance for this function to be preempted before reading the register, allowing a call to ts5500_gpio_direction_output to occur before ts5500_gpio_get is completed?
Vivien.
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