[PATCH] staging: greybus: use sysfs_emit instead of sprintf in gbphy.c

[PATCH] staging: greybus: use sysfs_emit instead of sprintf in gbphy.c

[Tomasz Unger]

Per Documentation/filesystems/sysfs.rst, new implementations of
show() methods should only use sysfs_emit() or sysfs_emit_at()
when formatting the value to be returned to user space, since it
is aware of the sysfs PAGE_SIZE buffer and includes sanity checks
that sprintf() lacks.

Signed-off-by: Tomasz Unger <tomasz.unger@yahoo.pl>
---
Verified with checkpatch.pl - no errors or warnings.
Compiled the gb-gbphy module successfully with CONFIG_GREYBUS=m
and CONFIG_GREYBUS_BRIDGED_PHY=m (both previously disabled).
Both greybus.ko and gb-gbphy.ko load without errors in a QEMU
environment (verified via insmod and lsmod). This confirms the
modules load cleanly but does not exercise the changed sysfs
show() code path, which would require an actual Greybus device
(or a userspace simulator such as gbsim) bound to the driver.
---
 drivers/staging/greybus/gbphy.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/greybus/gbphy.c b/drivers/staging/greybus/gbphy.c
index bdb0f5164a6f..bb9a5b538e6e 100644
--- a/drivers/staging/greybus/gbphy.c
+++ b/drivers/staging/greybus/gbphy.c
@@ -31,7 +31,7 @@ static ssize_t protocol_id_show(struct device *dev,
 {
 	struct gbphy_device *gbphy_dev = to_gbphy_dev(dev);
 
-	return sprintf(buf, "0x%02x\n", gbphy_dev->cport_desc->protocol_id);
+	return sysfs_emit(buf, "0x%02x\n", gbphy_dev->cport_desc->protocol_id);
 }
 static DEVICE_ATTR_RO(protocol_id);
 

---
base-commit: 8d3ae59288f1e7d58d76558a6ee96d533bc5019f
change-id: 20260818-greybus-gbphy-sysfs-emit-69739912458e

Best regards,
--  
Tomasz Unger <tomasz.unger@yahoo.pl>

Re: [PATCH] staging: greybus: use sysfs_emit instead of sprintf in gbphy.c

[Greg Kroah-Hartman]

On Tue, Aug 18, 2026 at 07:35:54PM +0200, Tomasz Unger wrote:
> Per Documentation/filesystems/sysfs.rst, new implementations of
> show() methods should only use sysfs_emit() or sysfs_emit_at()
> when formatting the value to be returned to user space, since it
> is aware of the sysfs PAGE_SIZE buffer and includes sanity checks
> that sprintf() lacks.
> 
> Signed-off-by: Tomasz Unger <tomasz.unger@yahoo.pl>
> ---
> Verified with checkpatch.pl - no errors or warnings.
> Compiled the gb-gbphy module successfully with CONFIG_GREYBUS=m
> and CONFIG_GREYBUS_BRIDGED_PHY=m (both previously disabled).
> Both greybus.ko and gb-gbphy.ko load without errors in a QEMU
> environment (verified via insmod and lsmod). This confirms the
> modules load cleanly but does not exercise the changed sysfs
> show() code path, which would require an actual Greybus device
> (or a userspace simulator such as gbsim) bound to the driver.
> ---
>  drivers/staging/greybus/gbphy.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/greybus/gbphy.c b/drivers/staging/greybus/gbphy.c
> index bdb0f5164a6f..bb9a5b538e6e 100644
> --- a/drivers/staging/greybus/gbphy.c
> +++ b/drivers/staging/greybus/gbphy.c
> @@ -31,7 +31,7 @@ static ssize_t protocol_id_show(struct device *dev,
>  {
>  	struct gbphy_device *gbphy_dev = to_gbphy_dev(dev);
>  
> -	return sprintf(buf, "0x%02x\n", gbphy_dev->cport_desc->protocol_id);
> +	return sysfs_emit(buf, "0x%02x\n", gbphy_dev->cport_desc->protocol_id);
>  }
>  static DEVICE_ATTR_RO(protocol_id);
>  
> 
> ---
> base-commit: 8d3ae59288f1e7d58d76558a6ee96d533bc5019f
> change-id: 20260818-greybus-gbphy-sysfs-emit-69739912458e
> 
> Best regards,
> --  
> Tomasz Unger <tomasz.unger@yahoo.pl>
> 
> 

Please see the archives for why this patch has been rejected in the
past.

thanks,

greg k-h