[v3] of: Make of framebuffer devices unique

Message ID 20230120180958.30798-1-msuchanek@suse.de
State New
Headers
Series [v3] of: Make of framebuffer devices unique |

Commit Message

Michal Suchánek Jan. 20, 2023, 6:09 p.m. UTC
  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@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@mailbox.org>
Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
---
v3:
- merge fix into original patch
- Update the device name format
- add missing const
- do not continue with iterating display devices when formatting device
  name fails
---
 drivers/of/platform.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)
  

Comments

Rob Herring Jan. 30, 2023, 4:50 p.m. UTC | #1
On Fri, 20 Jan 2023 19:09:57 +0100, Michal Suchanek 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@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@mailbox.org>
> Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
> Signed-off-by: Michal Suchanek <msuchanek@suse.de>
> ---
> v3:
> - merge fix into original patch
> - Update the device name format
> - add missing const
> - do not continue with iterating display devices when formatting device
>   name fails
> ---
>  drivers/of/platform.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 

Applied, thanks!
  

Patch

diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 81c8c227ab6b..4d3a4d9f79f2 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -525,6 +525,9 @@  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 = 0;
+		char buf[14];
+		const char *of_display_format = "of-display.%d";
 		int ret;
 
 		/* Check if we have a MacOS display without a node spec */
@@ -555,7 +558,10 @@  static int __init of_platform_default_populate_init(void)
 			if (!of_get_property(node, "linux,opened", NULL) ||
 			    !of_get_property(node, "linux,boot-display", NULL))
 				continue;
-			dev = of_platform_device_create(node, "of-display", NULL);
+			ret = snprintf(buf, sizeof(buf), of_display_format, display_number++);
+			if (ret >= sizeof(buf))
+				return -EOVERFLOW;
+			dev = of_platform_device_create(node, buf, NULL);
 			if (WARN_ON(!dev))
 				return -ENOMEM;
 			boot_display = node;
@@ -564,7 +570,10 @@  static int __init of_platform_default_populate_init(void)
 		for_each_node_by_type(node, "display") {
 			if (!of_get_property(node, "linux,opened", NULL) || node == boot_display)
 				continue;
-			of_platform_device_create(node, "of-display", NULL);
+			ret = snprintf(buf, sizeof(buf), of_display_format, display_number++);
+			if (ret >= sizeof(buf))
+				break;
+			of_platform_device_create(node, buf, NULL);
 		}
 
 	} else {