| Message ID | 1425656716-25363-1-git-send-email-iivanov@mm-sol.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Mar 06, 2015 at 05:45:15PM +0200, Ivan T. Ivanov wrote: > if (spi->master->setup) > status = spi->master->setup(spi); > + else > + spi_set_cs(spi, false); Why would this be conditional on there not being a setup operation? It's a good idea, I just don't see why the backstop isn't always useful.
On Sun, 2015-03-08 at 20:01 +0000, Mark Brown wrote: > On Fri, Mar 06, 2015 at 05:45:15PM +0200, Ivan T. Ivanov wrote: > > > if (spi->master->setup) > > status = spi->master->setup(spi); > > + else > > + spi_set_cs(spi, false); > > Why would this be conditional on there not being a setup operation? > It's a good idea, I just don't see why the backstop isn't always useful. I was thinking that this is expected to be handled inside setup operation, nothing more. Ivan -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Mar 9, 2015 at 9:11 AM, Ivan T. Ivanov <iivanov@mm-sol.com> wrote: > > On Sun, 2015-03-08 at 20:01 +0000, Mark Brown wrote: >> On Fri, Mar 06, 2015 at 05:45:15PM +0200, Ivan T. Ivanov wrote: >> >> > if (spi->master->setup) >> > status = spi->master->setup(spi); >> > + else >> > + spi_set_cs(spi, false); >> >> Why would this be conditional on there not being a setup operation? >> It's a good idea, I just don't see why the backstop isn't always useful. > > I was thinking that this is expected to be handled inside > setup operation, nothing more. Agree with Mark. It's perhaps a good idea to call unconditionally before ->setup().
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index c64a3e5..bfba2d9 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1895,6 +1895,8 @@ int spi_setup(struct spi_device *spi) if (spi->master->setup) status = spi->master->setup(spi); + else + spi_set_cs(spi, false); dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n", (int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
When drivers didn't provide setup() method, SPI core should ensure that CS line is driven in non-active state after spi_setup(). Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com> --- drivers/spi/spi.c | 2 ++ 1 file changed, 2 insertions(+) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html