diff mbox series

drm/bridge: ps8640: Fix size mismatch warning w/ len

Message ID 20231218090454.1.I5c6eb80b2f746439c4b58efab788e00701d08759@changeid
State New
Headers
Series drm/bridge: ps8640: Fix size mismatch warning w/ len |

Commit Message

Doug Anderson Dec. 18, 2023, 5:04 p.m. UTC 
  After commit 26195af57798 ("drm/bridge: ps8640: Drop the ability of
ps8640 to fetch the EDID"), I got an error compiling:

  error: comparison of distinct pointer types
  ('typeof (len) *' (aka 'unsigned int *') and
   'typeof (msg->size) *' (aka 'unsigned long *'))
  [-Werror,-Wcompare-distinct-pointer-types]

Fix it by declaring the `len` as size_t.

Fixes: 26195af57798 ("drm/bridge: ps8640: Drop the ability of ps8640 to fetch the EDID")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
Sorry for sending this hot on the heels of the other patch, but for
some reason that other patch compiled fine for me until I picked it
back to my downstream tree. I'll see if I can track down why. In any
case, as soon as I see a Reviewed-by tag I'll land this.

 drivers/gpu/drm/bridge/parade-ps8640.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Doug Anderson Dec. 18, 2023, 5:24 p.m. UTC | #1 
Hi,

On Mon, Dec 18, 2023 at 9:05 AM Douglas Anderson <dianders@chromium.org> wrote:
>
> After commit 26195af57798 ("drm/bridge: ps8640: Drop the ability of
> ps8640 to fetch the EDID"), I got an error compiling:
>
>   error: comparison of distinct pointer types
>   ('typeof (len) *' (aka 'unsigned int *') and
>    'typeof (msg->size) *' (aka 'unsigned long *'))
>   [-Werror,-Wcompare-distinct-pointer-types]
>
> Fix it by declaring the `len` as size_t.
>
> Fixes: 26195af57798 ("drm/bridge: ps8640: Drop the ability of ps8640 to fetch the EDID")
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---
> Sorry for sending this hot on the heels of the other patch, but for
> some reason that other patch compiled fine for me until I picked it
> back to my downstream tree. I'll see if I can track down why. In any
> case, as soon as I see a Reviewed-by tag I'll land this.

Ah, I found it! <Phew> this makes me less worried that I had some
failure in my testing. I believe that upstream things weren't a
problem because of commit d03eba99f5bf ("minmax: allow
min()/max()/clamp() if the arguments have the same signedness.").
...so at least what's landed isn't actually broken upstream, just
downstream. It still feels reasonable to change this to "size_t",
though.

-Doug
Stephen Boyd Dec. 19, 2023, 12:19 a.m. UTC | #2 
Quoting Douglas Anderson (2023-12-18 09:04:54)
> After commit 26195af57798 ("drm/bridge: ps8640: Drop the ability of
> ps8640 to fetch the EDID"), I got an error compiling:
>
>   error: comparison of distinct pointer types
>   ('typeof (len) *' (aka 'unsigned int *') and
>    'typeof (msg->size) *' (aka 'unsigned long *'))
>   [-Werror,-Wcompare-distinct-pointer-types]
>
> Fix it by declaring the `len` as size_t.
>
> Fixes: 26195af57798 ("drm/bridge: ps8640: Drop the ability of ps8640 to fetch the EDID")
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---

Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Doug Anderson Dec. 19, 2023, 3:15 p.m. UTC | #3 
Hi,

On Mon, Dec 18, 2023 at 9:05 AM Douglas Anderson <dianders@chromium.org> wrote:
>
> After commit 26195af57798 ("drm/bridge: ps8640: Drop the ability of
> ps8640 to fetch the EDID"), I got an error compiling:
>
>   error: comparison of distinct pointer types
>   ('typeof (len) *' (aka 'unsigned int *') and
>    'typeof (msg->size) *' (aka 'unsigned long *'))
>   [-Werror,-Wcompare-distinct-pointer-types]
>
> Fix it by declaring the `len` as size_t.
>
> Fixes: 26195af57798 ("drm/bridge: ps8640: Drop the ability of ps8640 to fetch the EDID")
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---
> Sorry for sending this hot on the heels of the other patch, but for
> some reason that other patch compiled fine for me until I picked it
> back to my downstream tree. I'll see if I can track down why. In any
> case, as soon as I see a Reviewed-by tag I'll land this.
>
>  drivers/gpu/drm/bridge/parade-ps8640.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

I've added a short explanation that the issue only shows up on
backports to kernels that don't have commit d03eba99f5bf ("minmax:
allow min()/max()/clamp() if the arguments have the same signedness.")
and landed this.

35ba6bd582cf drm/bridge: ps8640: Fix size mismatch warning w/ len
diff mbox series

Patch

diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c
index d264b80d909d..541e4f5afc4c 100644
--- a/drivers/gpu/drm/bridge/parade-ps8640.c
+++ b/drivers/gpu/drm/bridge/parade-ps8640.c
@@ -210,7 +210,7 @@  static ssize_t ps8640_aux_transfer_msg(struct drm_dp_aux *aux,
 	struct ps8640 *ps_bridge = aux_to_ps8640(aux);
 	struct regmap *map = ps_bridge->regmap[PAGE0_DP_CNTL];
 	struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;
-	unsigned int len = msg->size;
+	size_t len = msg->size;
 	unsigned int data;
 	unsigned int base;
 	int ret;