Messages in this thread | | | Date | Tue, 29 Jun 2021 18:07:41 +0100 | From | Mark Brown <> | Subject | Re: [PATCH] spi: atmel: Fix CS and initialization bug |
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On Tue, Jun 29, 2021 at 05:01:57PM +0000, Dan.Sneddon@microchip.com wrote: > On 6/29/21 9:47 AM, Mark Brown wrote:
> >In what way does it do that? I can't tell what the patch is supposed >to > >do.
> The SPI_MASTER_GPIO_SS flag has to be set so that the set_cs function > gets called even when using gpio cs pins.
This all needs to be clear in the changelog.
> >> - enable =3D (!!(spi->mode & SPI_CS_HIGH) =3D=3D enable); > >> =20 > >> - if (enable) { > >> + if ((enable && (spi->mode & SPI_CS_HIGH)) > >> + || (!enable && !(spi->mode & SPI_CS_HIGH))) {
> >This looks especially suspicious.
> It's due to the fact that the spi core tells set_cs if the cs should be > high or low, not active or disabled. This logic is to convert from > high/low to active/disabled.
spi_set_cs() handles SPI_CS_HIGH... this looks like a separate existing driver bug, it should just be ignoring SPI_CS_HIGH if it's providing a set_cs() operation and letting the core implement SPI_CS_HIGH for it. I only checked breifly but it looks like spi-atmel is trying to use the core support for chipselect handling here. [unhandled content-type:application/pgp-signature] | |