[PATCH] of: Make of framebuffer devices unique

[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 at suse.de> 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 at lists.ozlabs.org
> > 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 at mailbox.org>
> > Suggested-by: Thomas Zimmermann <tzimmermann at suse.de>
> > Signed-off-by: Michal Suchanek <msuchanek at suse.de>
> > ---
> >  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++);
> > +			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