RE: [PATCH 2/2] spi: img-spfi: fix spfi_setup by removing gpio_request_one

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Thanks Mark, Andrew.

I'll rework this and submit a new patch.

Thanks,
Sifan

> -----Original Message-----
> From: Mark Brown [mailto:broonie@xxxxxxxxxx]
> Sent: 27 July 2015 17:40
> To: Andrew Bresticker
> Cc: Sifan Naeem; linux-spi@xxxxxxxxxxxxxxx; Stable kernel (v4.1)
> Subject: Re: [PATCH 2/2] spi: img-spfi: fix spfi_setup by removing
> gpio_request_one
> 
> On Mon, Jul 27, 2015 at 09:34:41AM -0700, Andrew Bresticker wrote:
> > On Mon, Jul 27, 2015 at 5:11 AM, Sifan Naeem <sifan.naeem@xxxxxxxxxx>
> wrote:
> 
> > > spfi_setup may be called many times bye the spi framework, but
> > > gpio_request_one can only be called once without freeing, repeatedly
> > > calling gpio_request_one will cause an error to be thrown, which
> > > causes the request to spi_setup to be marked as failed.
> 
> > > We can simply use gpio_direction_output to set the direction of the
> > > gpio instead of gpio_request_one to put the gpio in to initial
> > > state, after which the spi framework can control the chipselect line
> > > via gpio using gpio_set_value.
> 
> > I don't think we want to leave the CS GPIOs un-requested.  Instead, we
> > could either request them all at probe() time (and then set direction
> > in setup()) or have a per-spi_device flag that indicates whether or
> > not the GPIO has been requested.
> 
> Not requesting the GPIOs at all would just be a straight up bug.
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