FAILED: patch "[PATCH] USB: bcma: Make GPIO explicitly optional" failed to apply to 4.9-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

Possible dependencies:

cd136706b4f9 ("USB: bcma: Make GPIO explicitly optional")
d91adc5322ab ("Revert "USB: bcma: Add a check for devm_gpiod_get"")
f3de5d857bb2 ("USB: bcma: Add a check for devm_gpiod_get")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From cd136706b4f925aa5d316642543babac90d45910 Mon Sep 17 00:00:00 2001
From: Linus Walleij <linus.walleij@linaro.org>
Date: Mon, 7 Nov 2022 10:07:53 +0100
Subject: [PATCH] USB: bcma: Make GPIO explicitly optional
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

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>

diff --git a/drivers/usb/host/bcma-hcd.c b/drivers/usb/host/bcma-hcd.c
index 2df52f75f6b3..7558cc4d90cc 100644
--- a/drivers/usb/host/bcma-hcd.c
+++ b/drivers/usb/host/bcma-hcd.c
@@ -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: