Hello Christophe,

On 2024-08-21 13:17, Christophe JAILLET wrote:

Le 21/08/2024 à 09:37, Dragan Simic a écrit :

quoted

Return the actual error code upon failure to allocate extcon device, 
instead
of hardcoding -ENOMEM.  Use dev_err_probe() to also log appropriate 
messages,
which is fine because the containing function is used in the probe 
path.

Helped-by: Heiko Stubner [off-list ref]
Signed-off-by: Dragan Simic <redacted>
---
  drivers/phy/rockchip/phy-rockchip-inno-usb2.c | 3 ++-
  1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/phy/rockchip/phy-rockchip-inno-usb2.c 

b/drivers/phy/rockchip/phy-rockchip-inno-usb2.c
index 113bfc717ff0..05af46dda11d 100644

--- a/drivers/phy/rockchip/phy-rockchip-inno-usb2.c
+++ b/drivers/phy/rockchip/phy-rockchip-inno-usb2.c

@@ -435,7 +435,8 @@ static int rockchip_usb2phy_extcon_register(struct 

rockchip_usb2phy *rphy)
  						rockchip_usb2phy_extcon_cable);
    		if (IS_ERR(edev))
-			return -ENOMEM;
+			return dev_err_probe(rphy->dev, PTR_ERR(edev),
+					     "failed to allocate extcon device\n");

Returning PTR_ERR(edev) may make sense, but I don't think that adding
a dev_err_probe() really helps.

devm_extcon_dev_allocate() can only return -EINVAL if it 2nd argument
is NULL. It is trivial to see that it can't happen here,
rockchip_usb2phy_extcon_cable is a global variable.

in all other cases, it returns -ENOMEM because of a failed memory
allocation. In this case, usually it is not needed to log anything
because it is already loud enough.

True, using dev_err_probe() in this case is somewhat redundant,
but it falls under the "still fine to use" category, [1] because
the error code passed to dev_err_probe() is received from another
function that was invoked.

On the other hand, another patch in this series tries to be strict
in another direction, by not using dev_err_probe() where the error
code passed to it is basically hardcoded. [2]

I hope this makes sense.

[1] 
https://lore.kernel.org/linux-phy/cover.1724225528.git.dsimic@manjaro.org/T/#mc3af7d24e31ed885732e6f26ca0d107b157d478b (local)
[2] 
https://lore.kernel.org/linux-phy/cover.1724225528.git.dsimic@manjaro.org/T/#ma26b614412787814dab7923987b8c814f7e86beb (local)

quoted

    		ret = devm_extcon_dev_register(rphy->dev, edev);
  		if (ret) {