iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

USB: bcma: Make GPIO explicitly optional

Browse Source 
What the code does is to not check the return value from
devm_gpiod_get() and then avoid using an erroneous GPIO descriptor
with IS_ERR_OR_NULL().

This will miss real errors from the GPIO core that should not be
ignored, such as probe deferral.

Instead request the GPIO as explicitly optional, which means that
if it doesn't exist, the descriptor returned will be NULL.

Then we can add error handling and also avoid just doing this on
the device tree path, and simplify the site where the optional
GPIO descriptor is used.

There were some problems with cleaning up this GPIO descriptor
use in the past, but this is the proper way to deal with it.

Cc: Rafał Miłecki <rafal@milecki.pl>
Cc: Chuhong Yuan <hslester96@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20221107090753.1404679-1-linus.walleij@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Linus Walleij 2022-11-07 10:07:53 +01:00 committed by Greg Kroah-Hartman
parent 30a0b95b13
commit cd136706b4
1 changed files with 6 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
drivers/usb/host/bcma-hcd.c
View File

@ -285,7 +285,7 @@ static void bcma_hci_platform_power_gpio(struct bcma_device *dev, bool val)
{
struct bcma_hcd_device *usb_dev = bcma_get_drvdata(dev);
if (IS_ERR_OR_NULL(usb_dev->gpio_desc))
if (!usb_dev->gpio_desc)
return;
gpiod_set_value(usb_dev->gpio_desc, val);
@ -406,9 +406,11 @@ static int bcma_hcd_probe(struct bcma_device *core)
return -ENOMEM;
usb_dev->core = core;
if (core->dev.of_node)
usb_dev->gpio_desc = devm_gpiod_get(&core->dev, "vcc",
GPIOD_OUT_HIGH);
usb_dev->gpio_desc = devm_gpiod_get_optional(&core->dev, "vcc",
GPIOD_OUT_HIGH);
if (IS_ERR(usb_dev->gpio_desc))
return dev_err_probe(&core->dev, PTR_ERR(usb_dev->gpio_desc),
"error obtaining VCC GPIO");
switch (core->id.id) {
case BCMA_CORE_USB20_HOST: