[PATCH v7 07/12] spi: Use helper for safer setting of driver_override

Krzysztof Kozlowski
2022-04-19T11:35:34Z

Use a helper to set driver_override to the reduce amount of duplicated
code.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
---
drivers/spi/spi.c | 26 ++++----------------------
include/linux/spi/spi.h | 2 ++
2 files changed, 6 insertions(+), 22 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 890ff46c784a..be8f1a1e21b2 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -71,29 +71,11 @@ static ssize_t driver_override_store(struct device *dev,
const char *buf, size_t count)
{
struct spi_device *spi = to_spi_device(dev);
- const char *end = memchr(buf, '\n', count);
- const size_t len = end ? end - buf : count;
- const char *driver_override, *old;
-
- /* We need to keep extra room for a newline when displaying value */
- if (len >= (PAGE_SIZE - 1))
- return -EINVAL;
-
- driver_override = kstrndup(buf, len, GFP_KERNEL);
- if (!driver_override)
- return -ENOMEM;
+ int ret;

- device_lock(dev);
- old = spi->driver_override;
- if (len) {
- spi->driver_override = driver_override;
- } else {
- /* Empty string, disable driver override */
- spi->driver_override = NULL;
- kfree(driver_override);
- }
- device_unlock(dev);
- kfree(old);
+ ret = driver_set_override(dev, &spi->driver_override, buf, count);
+ if (ret)
+ return ret;

return count;
}
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 5f8c063ddff4..f0177f9b6e13 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -138,6 +138,8 @@ extern int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer);
* for driver coldplugging, and in uevents used for hotplugging
* @driver_override: If the name of a driver is written to this attribute, then
* the device will bind to the named driver and only the named driver.
+ * Do not set directly, because core frees it; use driver_set_override() to
+ * set or clear it.
* @cs_gpiod: gpio descriptor of the chipselect line (optional, NULL when
* not using a GPIO line)
* @word_delay: delay to be inserted between consecutive
--
2.32.0