Re: [PATCH 3/4] net: can: mcp251x: use new GPIO line value setter callbacks
From: Bartosz Golaszewski <hidden>
Date: 2025-06-10 14:05:58
Also in:
linux-arm-kernel, linux-arm-msm, linux-can, linux-gpio, linux-mediatek, lkml
On Tue, Jun 10, 2025 at 3:55 PM Vincent Mailhol [off-list ref] wrote:
On 10/06/2025 at 21:37, Bartosz Golaszewski wrote:quoted
From: Bartosz Golaszewski <redacted> struct gpio_chip now has callbacks for setting line values that return an integer, allowing to indicate failures. Convert the driver to using them. Signed-off-by: Bartosz Golaszewski <redacted>^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ This does not match the address with which you sent the patch: brgl@bgdev.plquoted
--- drivers/net/can/spi/mcp251x.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c index ec5c64006a16f703bc816983765584c5f3ac76e8..7545497d14b46c6388f3976c2bf7b9a99e959c1e 100644 --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c@@ -530,8 +530,8 @@ static int mcp251x_gpio_get_multiple(struct gpio_chip *chip, return 0; } -static void mcp251x_gpio_set(struct gpio_chip *chip, unsigned int offset, - int value) +static int mcp251x_gpio_set(struct gpio_chip *chip, unsigned int offset, + int value) { struct mcp251x_priv *priv = gpiochip_get_data(chip); u8 mask, val;@@ -545,9 +545,11 @@ static void mcp251x_gpio_set(struct gpio_chip *chip, unsigned int offset, priv->reg_bfpctrl &= ~mask; priv->reg_bfpctrl |= val; + + return 0;mcp251x_gpio_set() calls mcp251x_write_bits() which calls mcp251x_spi_write() which can fail. For this change to really make sense, the return value of mcp251x_spi_write() should be propagated all the way around.
I don't know this code so I followed the example of the rest of the codebase where the result of this function is never checked - even in functions that do return values. I didn't know the reason for this and so didn't want to break anything as I have no means of testing it. Can you confirm that you really want the result to be checked here? Bart