Re: [PATCH] drm/appletbdrm: Fix format specifier for size_t variables

From: Jani Nikula
Date: Tue Mar 04 2025 - 09:17:24 EST


On Tue, 04 Mar 2025, Nathan Chancellor <nathan@xxxxxxxxxx> wrote:
> When building for a 32-bit platform, there are some warnings (or errors
> with CONFIG_WERROR=y) due to an incorrect specifier for 'size_t'
> variables, which is typedef'd as 'unsigned int' for these architectures:
>
> drivers/gpu/drm/tiny/appletbdrm.c:171:17: error: format specifies type 'unsigned long' but the argument has type 'size_t' (aka 'unsigned int') [-Werror,-Wformat]
> 170 | drm_err(drm, "Actual size (%d) doesn't match expected size (%lu)\n",
> | ~~~
> | %zu
> 171 | actual_size, size);
> | ^~~~
> ...
> drivers/gpu/drm/tiny/appletbdrm.c:212:17: error: format specifies type 'unsigned long' but the argument has type 'size_t' (aka 'unsigned int') [-Werror,-Wformat]
> 211 | drm_err(drm, "Actual size (%d) doesn't match expected size (%lu)\n",
> | ~~~
> | %zu
> 212 | actual_size, size);
> | ^~~~
>
> Use '%zu' as suggested, clearing up the warnings.
>
> Fixes: 0670c2f56e45 ("drm/tiny: add driver for Apple Touch Bars in x86 Macs")
> Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>

Just sent an identical patch [1]. :)

You have a better commit message, let's go with this. With Aditya's ack
from the other thread,

Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Acked-by: Aditya Garg <gargaditya08@xxxxxxxx>

[1] https://lore.kernel.org/r/20250304135456.429407-1-jani.nikula@xxxxxxxxx

> ---
> drivers/gpu/drm/tiny/appletbdrm.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/tiny/appletbdrm.c b/drivers/gpu/drm/tiny/appletbdrm.c
> index f5d177e234e4..394c8f9bd41a 100644
> --- a/drivers/gpu/drm/tiny/appletbdrm.c
> +++ b/drivers/gpu/drm/tiny/appletbdrm.c
> @@ -167,7 +167,7 @@ static int appletbdrm_send_request(struct appletbdrm_device *adev,
> }
>
> if (actual_size != size) {
> - drm_err(drm, "Actual size (%d) doesn't match expected size (%lu)\n",
> + drm_err(drm, "Actual size (%d) doesn't match expected size (%zu)\n",
> actual_size, size);
> return -EIO;
> }
> @@ -208,7 +208,7 @@ static int appletbdrm_read_response(struct appletbdrm_device *adev,
> }
>
> if (actual_size != size) {
> - drm_err(drm, "Actual size (%d) doesn't match expected size (%lu)\n",
> + drm_err(drm, "Actual size (%d) doesn't match expected size (%zu)\n",
> actual_size, size);
> return -EBADMSG;
> }
>
> ---
> base-commit: 95a5c9d197bb22a506913acb330a926d4e51aa95
> change-id: 20250304-appletbdrm-fix-size_t-specifier-d3c547522379
>
> Best regards,

--
Jani Nikula, Intel