diff mbox series

[v1] spi: xtensa-xtfpga: Fix a double put() in xtfpga_spi_remove()

Message ID 7946a26c6e53a4158f0f5bad5276d8654fd59415.1670673147.git.christophe.jaillet@wanadoo.fr
State New
Headers
Series [v1] spi: xtensa-xtfpga: Fix a double put() in xtfpga_spi_remove() |

Commit Message

Christophe JAILLET Dec. 10, 2022, 11:52 a.m. UTC 
  'master' is allocated with devm_spi_alloc_master(), there is no need to
put it explicitly in the remove function.

Fixes: 478cc2fc3dd7 ("spi: xtensa-xtfpga: Switch to use devm_spi_alloc_master()")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
 drivers/spi/spi-xtensa-xtfpga.c | 1 -
 1 file changed, 1 deletion(-)

Comments

Max Filippov Dec. 10, 2022, 2:48 p.m. UTC | #1 
Hi Christophe,

On Sat, Dec 10, 2022 at 3:52 AM Christophe JAILLET
<christophe.jaillet@wanadoo.fr> wrote:
>
> 'master' is allocated with devm_spi_alloc_master(), there is no need to
> put it explicitly in the remove function.
>
> Fixes: 478cc2fc3dd7 ("spi: xtensa-xtfpga: Switch to use devm_spi_alloc_master()")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
>  drivers/spi/spi-xtensa-xtfpga.c | 1 -
>  1 file changed, 1 deletion(-)
>
> diff --git a/drivers/spi/spi-xtensa-xtfpga.c b/drivers/spi/spi-xtensa-xtfpga.c
> index 2fa7608f94cd..271ae98f441c 100644
> --- a/drivers/spi/spi-xtensa-xtfpga.c
> +++ b/drivers/spi/spi-xtensa-xtfpga.c
> @@ -123,7 +123,6 @@ static int xtfpga_spi_remove(struct platform_device *pdev)
>         struct xtfpga_spi *xspi = spi_master_get_devdata(master);
>
>         spi_bitbang_stop(&xspi->bitbang);
> -       spi_master_put(master);

This put is matching the get in the spi_bitbang_start.
It was discussed here:
https://lore.kernel.org/linux-spi/CAMo8BfJaD7pG_iutY8jordysjChyzhTpVSqpxXh3QoZsj2QmaQ@mail.gmail.com/
Mark Brown Dec. 12, 2022, 3:36 p.m. UTC | #2 
On Sat, Dec 10, 2022 at 06:48:02AM -0800, Max Filippov wrote:
> Hi Christophe,
> 
> On Sat, Dec 10, 2022 at 3:52 AM Christophe JAILLET
> <christophe.jaillet@wanadoo.fr> wrote:

> > 'master' is allocated with devm_spi_alloc_master(), there is no need to
> > put it explicitly in the remove function.

> >         spi_bitbang_stop(&xspi->bitbang);
> > -       spi_master_put(master);

> This put is matching the get in the spi_bitbang_start.
> It was discussed here:
> https://lore.kernel.org/linux-spi/CAMo8BfJaD7pG_iutY8jordysjChyzhTpVSqpxXh3QoZsj2QmaQ@mail.gmail.com/

Probably worth a comment though since it is a bit of a gotcha.  Ideally
we'd improve this in the bitbang code but that's harder.
Mark Brown Dec. 13, 2022, 11:40 a.m. UTC | #3 
On Tue, Dec 13, 2022 at 09:30:32AM +0800, Yang Yingliang wrote:
> On 2022/12/12 23:36, Mark Brown wrote:
> > On Sat, Dec 10, 2022 at 06:48:02AM -0800, Max Filippov wrote:

> > Probably worth a comment though since it is a bit of a gotcha.  Ideally
> > we'd improve this in the bitbang code but that's harder.

> Ideally, spi_bitbang_stop() should undo spi_bitbang_start(). shall we move
> spi_master_put() in spi_bitbang_stop() instead of
> calling it separately in drivers?

Ideally like I say, there's issues with devm IIRC which make it more
complicated than just adding a put() there.
diff mbox series

Patch

diff --git a/drivers/spi/spi-xtensa-xtfpga.c b/drivers/spi/spi-xtensa-xtfpga.c
index 2fa7608f94cd..271ae98f441c 100644
--- a/drivers/spi/spi-xtensa-xtfpga.c
+++ b/drivers/spi/spi-xtensa-xtfpga.c
@@ -123,7 +123,6 @@  static int xtfpga_spi_remove(struct platform_device *pdev)
 	struct xtfpga_spi *xspi = spi_master_get_devdata(master);
 
 	spi_bitbang_stop(&xspi->bitbang);
-	spi_master_put(master);
 
 	return 0;
 }