Re: [PATCH v1] Input: ads7846: ads7846_get_value - fix unaligned pointer value warning
From: Oleksij Rempel <o.rempel@pengutronix.de>
Date: 2021-09-10 07:52:04
Also in:
linux-input, lkml
Hi Dmitry, On Thu, Sep 09, 2021 at 10:04:16PM -0700, Dmitry Torokhov wrote:
Hi Oleksij, On Wed, Jul 07, 2021 at 02:41:15PM +0200, Oleksij Rempel wrote:quoted
Fix warning reported by the kernel test robot: drivers/input/touchscreen/ads7846.c:705:24: warning: taking address of packed member 'data' of class or structure 'ads7846_buf' may result in an unaligned pointer value [-Waddress-of-packed-member] Fixes: 6965eece2a89 ("Input: ads7846 - convert to one message") Reported-by: kernel test robot <redacted> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> --- drivers/input/touchscreen/ads7846.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index adb4c2230c31..1987dedac94f 100644 --- a/drivers/input/touchscreen/ads7846.c +++ b/drivers/input/touchscreen/ads7846.c@@ -702,7 +702,7 @@ static int ads7846_get_value(struct ads7846_buf *buf) { int value; - value = be16_to_cpup(&buf->data); + value = get_unaligned_be16(&buf->data);ds7846_buf is declared as packed so I believe using be16_to_cpu(buf->data) will suffice.
The pointer to the data is is off by 8 bits, so it is not naturally aligned. This is why we need to use function which is dealing with unaligned pointers. Regards, Oleksij -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |