| Message ID | 20210420131901.80233-1-andriy.shevchenko@linux.intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v1,1/1] spi: Don't overwrite num_chipselect with error code | expand |
On Tue, Apr 20, 2021 at 4:19 PM Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote: > > The code currently organized in a way that num_chipselect is overwritten > each time we call spi_get_gpio_descs(). It might be potentially dangerous > in case when the gpiod_count() returns an error code. > > Note, that gpiod_count() never returns 0, take this into account as well. > > Fixes: f3186dd87669 ("spi: Optionally use GPIO descriptors for CS GPIOs") It doesn't fix anything. I missed the max_t(int). In any case it makes error handling cleaner, so I'll reformulate the commit message in v2 and drop Fixes tag.
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);
The code currently organized in a way that num_chipselect is overwritten each time we call spi_get_gpio_descs(). It might be potentially dangerous in case when the gpiod_count() returns an error code. Note, that gpiod_count() never returns 0, take this into account as well. Fixes: f3186dd87669 ("spi: Optionally use GPIO descriptors for CS GPIOs") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- drivers/spi/spi.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-)