[PATCH v2 1/1] spi: Make error handling of gpiod_count() call cleaner

[PATCH v2 1/1] spi: Make error handling of gpiod_count() call cleaner

[Andy Shevchenko]

Each time we call spi_get_gpio_descs() the num_chipselect is overwritten
either by new value or by the old one. This is an extra operation in case
gpiod_count() returns an error. Besides that it slashes the error handling
of gpiod_count().

Refactor the code to make error handling of gpiod_count() call cleaner.

Note, that gpiod_count() never returns 0, take this into account as well.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
v2: reformulated commit message and dropped Fixes tag
 drivers/spi/spi.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 74b2b1dd358b..36c46feab6d4 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -2558,13 +2558,14 @@ static int spi_get_gpio_descs(struct spi_controller *ctlr)
 	unsigned int num_cs_gpios = 0;
 
 	nb = gpiod_count(dev, "cs");
-	ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
-
-	/* No GPIOs at all is fine, else return the error */
-	if (nb == 0 || nb == -ENOENT)
-		return 0;
-	else if (nb < 0)
+	if (nb < 0) {
+		/* No GPIOs at all is fine, else return the error */
+		if (nb == -ENOENT)
+			return 0;
 		return nb;
+	}
+
+	ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
 
 	cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs),
 			  GFP_KERNEL);
-- 
2.30.2

Re: [PATCH v2 1/1] spi: Make error handling of gpiod_count() call cleaner

[Mark Brown]

On Tue, 20 Apr 2021 19:40:40 +0300, Andy Shevchenko wrote:
> Each time we call spi_get_gpio_descs() the num_chipselect is overwritten
> either by new value or by the old one. This is an extra operation in case
> gpiod_count() returns an error. Besides that it slashes the error handling
> of gpiod_count().
> 
> Refactor the code to make error handling of gpiod_count() call cleaner.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/1] spi: Make error handling of gpiod_count() call cleaner
      commit: 31ed8ebc7a27c1937184b956727bf71d4adc7df3

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark