Re: [PATCH] of: Make of framebuffer devices unique

[Thomas Zimmermann]

Hi Michal,

thanks for fixing this issue. But the review time was way too short. 
Please see my comments below.

Am 18.01.23 um 22:46 schrieb Michal Suchánek:
> On Wed, Jan 18, 2023 at 09:13:05PM +0100, Erhard F. wrote:
> > On Tue, 17 Jan 2023 17:58:04 +0100
> > Michal Suchanek <msuchanek@xxxxxxx> wrote:
> >
> > > Since Linux 5.19 this error is observed:
> > >
> > > sysfs: cannot create duplicate filename '/devices/platform/of-display'
> > >
> > > This is because multiple devices with the same name 'of-display' are
> > > created on the same bus.
> > >
> > > Update the code to create numbered device names for the non-boot
> > > disaplay.
> > >
> > > cc: linuxppc-dev@xxxxxxxxxxxxxxxx
> > > References: https://bugzilla.kernel.org/show_bug.cgi?id=216095
> > > Fixes: 52b1b46c39ae ("of: Create platform devices for OF framebuffers")
> > > Reported-by: Erhard F. <erhard_f@xxxxxxxxxxx>
> > > Suggested-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> > > Signed-off-by: Michal Suchanek <msuchanek@xxxxxxx>
> > > ---
> > >   drivers/of/platform.c | 8 +++++++-
> > >   1 file changed, 7 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> > > index 81c8c227ab6b..f2a5d679a324 100644
> > > --- a/drivers/of/platform.c
> > > +++ b/drivers/of/platform.c
> > > @@ -525,6 +525,7 @@ static int __init of_platform_default_populate_init(void)
> > >   	if (IS_ENABLED(CONFIG_PPC)) {
> > >   		struct device_node *boot_display = NULL;
> > >   		struct platform_device *dev;
> > > +		int display_number = 1;
> > >   		int ret;
> > >   
> > >   		/* Check if we have a MacOS display without a node spec */
> > > @@ -561,10 +562,15 @@ static int __init of_platform_default_populate_init(void)
> > >   			boot_display = node;
> > >   			break;
> > >   		}
> > > +
> > >   		for_each_node_by_type(node, "display") {
> > > +			char *buf[14];
> > >   			if (!of_get_property(node, "linux,opened", NULL) || node == boot_display)
> > >   				continue;
> > > -			of_platform_device_create(node, "of-display", NULL);
> > > +			ret = snprintf(buf, "of-display-%d", display_number++);

Platform devices use a single dot (.) as separator before the index. 
Counting starts at zero. See /sys/bus/platform/ for examples. Can we 
please stick with that scheme? Generated names would then be 
of-display.0, of-display.1, etc.

Best regards
Thomas



> > > +			if (ret >= sizeof(buf))
> > > +				continue;
> > > +			of_platform_device_create(node, buf, NULL);
> > >   		}
> > >   
> > >   	} else {
> > > --
> > > 2.35.3
> >
> > Thank you for the patch Michal!
> >
> > It applies on 6.2-rc4 but I get this build error with my config:
>
> Indeed, it's doubly bad.
>
> Where is the kernel test robot when you need it?
>
> It should not be that easy to miss this file but clearly it can happen.
>
> I will send a fixup.
>
> Sorry about the mess.
>
> Thanks
>
> Michal

--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev

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