2020-11-12 01:45:24

by Dmitry Torokhov

Subject: [PATCH] Input: ads7846 - fix unaligned access on 7845

req->sample[1] is not naturally aligned at word boundary, and therefore
we should use get_unaligned_be16() when accessing it.

Fixes: 3eac5c7e44f3 ("Input: ads7846 - extend the driver for ads7845 controller support")
Signed-off-by: Dmitry Torokhov <[email protected]>
---

Not tested on hardware, so if somebody has the controller and can verify
that would be great.


drivers/input/touchscreen/ads7846.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 95e89f675ad5..35d14bc44aff 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -33,6 +33,7 @@
#include <linux/regulator/consumer.h>
#include <linux/module.h>
#include <asm/irq.h>
+#include <asm/unaligned.h>

/*
* This code has been heavily tested on a Nokia 770, and lightly
@@ -443,7 +444,7 @@ static int ads7845_read12_ser(struct device *dev, unsigned command)

if (status == 0) {
/* BE12 value, then padding */
- status = be16_to_cpu(*((u16 *)&req->sample[1]));
+ status = get_unaligned_be16(&req->sample[1]);
status = status >> 3;
status &= 0x0fff;
}
--
2.29.2.222.g5d2a92d10f8-goog


--
Dmitry

2020-11-12 08:06:11

by Oleksij Rempel

Subject: Re: [PATCH] Input: ads7846 - fix unaligned access on 7845

Hello Dmitry,

Am 12.11.20 um 02:27 schrieb Dmitry Torokhov:
> req->sample[1] is not naturally aligned at word boundary, and therefore
> we should use get_unaligned_be16() when accessing it.
>
> Fixes: 3eac5c7e44f3 ("Input: ads7846 - extend the driver for ads7845 controller support")
> Signed-off-by: Dmitry Torokhov <[email protected]>

I do not have ads7845, but i assume i need to resend my patch with the same fix. Correct?

> ---
>
> Not tested on hardware, so if somebody has the controller and can verify
> that would be great.
>
>
> drivers/input/touchscreen/ads7846.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
> index 95e89f675ad5..35d14bc44aff 100644
> --- a/drivers/input/touchscreen/ads7846.c
> +++ b/drivers/input/touchscreen/ads7846.c
> @@ -33,6 +33,7 @@
> #include <linux/regulator/consumer.h>
> #include <linux/module.h>
> #include <asm/irq.h>
> +#include <asm/unaligned.h>
>
> /*
> * This code has been heavily tested on a Nokia 770, and lightly
> @@ -443,7 +444,7 @@ static int ads7845_read12_ser(struct device *dev, unsigned command)
>
> if (status == 0) {
> /* BE12 value, then padding */
> - status = be16_to_cpu(*((u16 *)&req->sample[1]));
> + status = get_unaligned_be16(&req->sample[1]);
> status = status >> 3;
> status &= 0x0fff;
> }
>


--
Regards,
Oleksij

2020-11-18 00:35:46

by Dmitry Torokhov

Subject: Re: [PATCH] Input: ads7846 - fix unaligned access on 7845

On Thu, Nov 12, 2020 at 09:04:23AM +0100, Oleksij Rempel wrote:
> Hello Dmitry,
>
> Am 12.11.20 um 02:27 schrieb Dmitry Torokhov:
> > req->sample[1] is not naturally aligned at word boundary, and therefore
> > we should use get_unaligned_be16() when accessing it.
> >
> > Fixes: 3eac5c7e44f3 ("Input: ads7846 - extend the driver for ads7845 controller support")
> > Signed-off-by: Dmitry Torokhov <[email protected]>
>
> I do not have ads7845, but i assume i need to resend my patch with the same fix. Correct?

I do not think your patches are affected, so I just applied it together
with yours.

Thanks.

--
Dmitry