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    SubjectRe: [v2 2/4] platform: (TS-5500) add GPIO support
    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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