ARM: 6214/2: fix release_mem_region() size

[PATCH] ARM: 6214/2: fix release_mem_region() size

Posted by Thomas Fourier 1 month, 3 weeks ago

It seems like, after the request_mem_region(), the corresponding
release_mem_region() must take the same size. This was done
in charlcd_remove() but not in the error path in charlcd_probe().

Fixes: ce8962455e90 ("ARM: 6214/2: driver for the character LCD found in ARM refdesigns")
Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
---
 drivers/auxdisplay/arm-charlcd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/auxdisplay/arm-charlcd.c b/drivers/auxdisplay/arm-charlcd.c
index a7eae99a48f7..4e22882f57c9 100644
--- a/drivers/auxdisplay/arm-charlcd.c
+++ b/drivers/auxdisplay/arm-charlcd.c
@@ -323,7 +323,7 @@ static int __init charlcd_probe(struct platform_device *pdev)
 out_no_irq:
 	iounmap(lcd->virtbase);
 out_no_memregion:
-	release_mem_region(lcd->phybase, SZ_4K);
+	release_mem_region(lcd->phybase, lcd->physize);
 out_no_resource:
 	kfree(lcd);
 	return ret;
-- 
2.43.0

Re: [PATCH] ARM: 6214/2: fix release_mem_region() size

Posted by Andy Shevchenko 1 month, 1 week ago

On Tue, Dec 16, 2025 at 06:47:13PM +0100, Thomas Fourier wrote:
> It seems like, after the request_mem_region(), the corresponding
> release_mem_region() must take the same size. This was done
> in charlcd_remove() but not in the error path in charlcd_probe().

Pushed to my review and testing queue, thanks!

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH] ARM: 6214/2: fix release_mem_region() size

Posted by Geert Uytterhoeven 1 month, 3 weeks ago

Hi Thomas,

Thanks for your patch!

The patch prefix should be "auxdisplay: arm-charlcd:", not an rmk
patch tracker ID.

On Tue, 16 Dec 2025 at 18:49, Thomas Fourier <fourier.thomas@gmail.com> wrote:
> It seems like, after the request_mem_region(), the corresponding
> release_mem_region() must take the same size. This was done
> in charlcd_remove() but not in the error path in charlcd_probe().

Unfortunately charlcd_remove() was removed in one of these silly
"make <foo> explicitly non-modular" patches...

> Fixes: ce8962455e90 ("ARM: 6214/2: driver for the character LCD found in ARM refdesigns")
> Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>

> --- a/drivers/auxdisplay/arm-charlcd.c
> +++ b/drivers/auxdisplay/arm-charlcd.c
> @@ -323,7 +323,7 @@ static int __init charlcd_probe(struct platform_device *pdev)
>  out_no_irq:
>         iounmap(lcd->virtbase);
>  out_no_memregion:

Looks like the first "goto out_no_memregion" is incorrect, and should be
"goto out_no_resource".

> -       release_mem_region(lcd->phybase, SZ_4K);
> +       release_mem_region(lcd->phybase, lcd->physize);
>  out_no_resource:
>         kfree(lcd);
>         return ret;

The actual change LGTM to me, so
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH] ARM: 6214/2: fix release_mem_region() size

Posted by Andy Shevchenko 1 month, 1 week ago

On Wed, Dec 17, 2025 at 08:28:27AM +0100, Geert Uytterhoeven wrote:
> Hi Thomas,
> 
> Thanks for your patch!
> 
> The patch prefix should be "auxdisplay: arm-charlcd:", not an rmk
> patch tracker ID.
> 
> On Tue, 16 Dec 2025 at 18:49, Thomas Fourier <fourier.thomas@gmail.com> wrote:
> > It seems like, after the request_mem_region(), the corresponding
> > release_mem_region() must take the same size. This was done
> > in charlcd_remove() but not in the error path in charlcd_probe().
> 
> Unfortunately charlcd_remove() was removed in one of these silly
> "make <foo> explicitly non-modular" patches...
> 
> > Fixes: ce8962455e90 ("ARM: 6214/2: driver for the character LCD found in ARM refdesigns")
> > Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
> 
> > --- a/drivers/auxdisplay/arm-charlcd.c
> > +++ b/drivers/auxdisplay/arm-charlcd.c
> > @@ -323,7 +323,7 @@ static int __init charlcd_probe(struct platform_device *pdev)
> >  out_no_irq:
> >         iounmap(lcd->virtbase);
> >  out_no_memregion:
> 
> Looks like the first "goto out_no_memregion" is incorrect, and should be
> "goto out_no_resource".

Should it be in this change or in a separate change? I'm not sure I got what
should be done about this.

> > -       release_mem_region(lcd->phybase, SZ_4K);
> > +       release_mem_region(lcd->phybase, lcd->physize);
> >  out_no_resource:
> >         kfree(lcd);
> >         return ret;
> 
> The actual change LGTM to me, so
> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>

Reading between the lines, should I alter the commit message to mention that
there is no more charlcd_remove()? Something like:

    It seems like, after the request_mem_region(), the corresponding
    release_mem_region() must take the same size. This was done
    in recently dropped charlcd_remove() but not in the error path
    in charlcd_probe().

(and Subject line)?

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH] ARM: 6214/2: fix release_mem_region() size

Posted by Geert Uytterhoeven 1 month, 1 week ago

Hi Andy,

On Sat, 27 Dec 2025 at 17:01, Andy Shevchenko
<andriy.shevchenko@intel.com> wrote:
> On Wed, Dec 17, 2025 at 08:28:27AM +0100, Geert Uytterhoeven wrote:
> > On Tue, 16 Dec 2025 at 18:49, Thomas Fourier <fourier.thomas@gmail.com> wrote:
> > > It seems like, after the request_mem_region(), the corresponding
> > > release_mem_region() must take the same size. This was done
> > > in charlcd_remove() but not in the error path in charlcd_probe().
> >
> > Unfortunately charlcd_remove() was removed in one of these silly
> > "make <foo> explicitly non-modular" patches...
> >
> > > Fixes: ce8962455e90 ("ARM: 6214/2: driver for the character LCD found in ARM refdesigns")
> > > Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
> >
> > > --- a/drivers/auxdisplay/arm-charlcd.c
> > > +++ b/drivers/auxdisplay/arm-charlcd.c
> > > @@ -323,7 +323,7 @@ static int __init charlcd_probe(struct platform_device *pdev)
> > >  out_no_irq:
> > >         iounmap(lcd->virtbase);
> > >  out_no_memregion:
> >
> > Looks like the first "goto out_no_memregion" is incorrect, and should be
> > "goto out_no_resource".
>
> Should it be in this change or in a separate change? I'm not sure I got what
> should be done about this.

Separate change.

> > > -       release_mem_region(lcd->phybase, SZ_4K);
> > > +       release_mem_region(lcd->phybase, lcd->physize);
> > >  out_no_resource:
> > >         kfree(lcd);
> > >         return ret;
> >
> > The actual change LGTM to me, so
> > Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
>
> Reading between the lines, should I alter the commit message to mention that
> there is no more charlcd_remove()? Something like:
>
>     It seems like, after the request_mem_region(), the corresponding
>     release_mem_region() must take the same size. This was done
>     in recently dropped charlcd_remove() but not in the error path
>     in charlcd_probe().
>
> (and Subject line)?

Yes please.  It is very confusing to refer to a function that no longer exists.

Thanks!

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds