From: Dan Carpenter dan.carpenter@oracle.com
[ Upstream commit 4c07a5d7aeb39f559b29aa58ec9a8a5ab4282cb0 ]
When a function like devm_clk_get_optional() function returns both error pointers on error and NULL then the NULL return means that the optional feature is deliberately disabled. It is a special sort of success and should not trigger an error message. The surrounding code should be written to check for NULL and not crash.
On the other hand, if we encounter an error, then the probe from should clean up and return a failure.
In this code, if devm_clk_get_optional() returns an error pointer then the kernel will crash inside the call to:
clk_set_rate(qcadev->susclk, SUSCLK_RATE_32KHZ);
The error handling must be updated to prevent that.
Fixes: 77131dfec6af ("Bluetooth: hci_qca: Replace devm_gpiod_get() with devm_gpiod_get_optional()") Signed-off-by: Dan Carpenter dan.carpenter@oracle.com Signed-off-by: Marcel Holtmann marcel@holtmann.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/bluetooth/hci_qca.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c index 14e4d2eaf8959..568f7ec20b000 100644 --- a/drivers/bluetooth/hci_qca.c +++ b/drivers/bluetooth/hci_qca.c @@ -1941,17 +1941,17 @@ static int qca_serdev_probe(struct serdev_device *serdev) }
qcadev->susclk = devm_clk_get_optional(&serdev->dev, NULL); - if (!qcadev->susclk) { + if (IS_ERR(qcadev->susclk)) { dev_warn(&serdev->dev, "failed to acquire clk\n"); - } else { - err = clk_set_rate(qcadev->susclk, SUSCLK_RATE_32KHZ); - if (err) - return err; - - err = clk_prepare_enable(qcadev->susclk); - if (err) - return err; + return PTR_ERR(qcadev->susclk); } + err = clk_set_rate(qcadev->susclk, SUSCLK_RATE_32KHZ); + if (err) + return err; + + err = clk_prepare_enable(qcadev->susclk); + if (err) + return err;
err = hci_uart_register_device(&qcadev->serdev_hu, &qca_proto); if (err) {