2018-06-11 05:24:43

by Zhouyang Jia

Subject: [PATCH] Input: add error handling for da9052_reg_write

When da9052_reg_write fails, the lack of error-handling code may
cause unexpected results.

This patch adds error-handling code after calling da9052_reg_write.

Signed-off-by: Zhouyang Jia <[email protected]>
---
drivers/input/touchscreen/da9052_tsi.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/input/touchscreen/da9052_tsi.c b/drivers/input/touchscreen/da9052_tsi.c
index b5dfd594..60c82a0 100644
--- a/drivers/input/touchscreen/da9052_tsi.c
+++ b/drivers/input/touchscreen/da9052_tsi.c
@@ -319,8 +319,11 @@ static int da9052_ts_probe(struct platform_device *pdev)
static int da9052_ts_remove(struct platform_device *pdev)
{
struct da9052_tsi *tsi = platform_get_drvdata(pdev);
+ int error;

- da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x19);
+ error = da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x19);
+ if (error < 0)
+ return error;

da9052_free_irq(tsi->da9052, DA9052_IRQ_TSIREADY, tsi);
da9052_free_irq(tsi->da9052, DA9052_IRQ_PENDOWN, tsi);
--
2.7.4

2018-06-11 17:41:01

by Dmitry Torokhov

Subject: Re: [PATCH] Input: add error handling for da9052_reg_write

Hi Zhouyang,

On Mon, Jun 11, 2018 at 01:23:39PM +0800, Zhouyang Jia wrote:
> When da9052_reg_write fails, the lack of error-handling code may
> cause unexpected results.
>
> This patch adds error-handling code after calling da9052_reg_write.
>
> Signed-off-by: Zhouyang Jia <[email protected]>
> ---
> drivers/input/touchscreen/da9052_tsi.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/input/touchscreen/da9052_tsi.c b/drivers/input/touchscreen/da9052_tsi.c
> index b5dfd594..60c82a0 100644
> --- a/drivers/input/touchscreen/da9052_tsi.c
> +++ b/drivers/input/touchscreen/da9052_tsi.c
> @@ -319,8 +319,11 @@ static int da9052_ts_probe(struct platform_device *pdev)
> static int da9052_ts_remove(struct platform_device *pdev)
> {
> struct da9052_tsi *tsi = platform_get_drvdata(pdev);
> + int error;
>
> - da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x19);
> + error = da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x19);
> + if (error < 0)
> + return error;

No, this does not help anything. The remove() action must not fail
(really, having it return an int and not void was an API mistake made
long time ago), and thus returning early in and event of error failing
to communicate with the device is a mistake. You really want to release
the interrupts and memory and unregister input device before returning.

>
> da9052_free_irq(tsi->da9052, DA9052_IRQ_TSIREADY, tsi);
> da9052_free_irq(tsi->da9052, DA9052_IRQ_PENDOWN, tsi);
> --
> 2.7.4
>

Thanks.

--
Dmitry

2018-06-12 05:38:14

by Steve Twiss

Subject: RE: [PATCH] Input: add error handling for da9052_reg_write

On 11 June 2018 18:30 wrote Dmitry Torokhov

> Subject: Re: [PATCH] Input: add error handling for da9052_reg_write
>
> Hi Zhouyang,
>
> On Mon, Jun 11, 2018 at 01:23:39PM +0800, Zhouyang Jia wrote:
> > When da9052_reg_write fails, the lack of error-handling code may
> > cause unexpected results.
> >
> > This patch adds error-handling code after calling da9052_reg_write.
> >
> > Signed-off-by: Zhouyang Jia <[email protected]>
> > ---
> > drivers/input/touchscreen/da9052_tsi.c | 5 ++++-
> > 1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/input/touchscreen/da9052_tsi.c
> b/drivers/input/touchscreen/da9052_tsi.c
> > index b5dfd594..60c82a0 100644
> > --- a/drivers/input/touchscreen/da9052_tsi.c
> > +++ b/drivers/input/touchscreen/da9052_tsi.c
> > @@ -319,8 +319,11 @@ static int da9052_ts_probe(struct platform_device *pdev)
> > static int da9052_ts_remove(struct platform_device *pdev)
> > {
> > struct da9052_tsi *tsi = platform_get_drvdata(pdev);
> > + int error;
> >
> > - da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x19);
> > + error = da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x19);
> > + if (error < 0)
> > + return error;
>
> No, this does not help anything. The remove() action must not fail
> (really, having it return an int and not void was an API mistake made
> long time ago), and thus returning early in and event of error failing
> to communicate with the device is a mistake. You really want to release
> the interrupts and memory and unregister input device before returning.
>
> >
> > da9052_free_irq(tsi->da9052, DA9052_IRQ_TSIREADY, tsi);
> > da9052_free_irq(tsi->da9052, DA9052_IRQ_PENDOWN, tsi);
> > --
> > 2.7.4
> >

script?
https://patchwork.kernel.org/project/LKML/list/?submitter=181001