usb: common: ulpi: Fix crash in ulpi_match()

Commit 7495af930835 ("ARM: multi_v7_defconfig: Enable drivers for
DragonBoard 410c") enables the CONFIG_PHY_QCOM_USB_HS for the ARM
multi_v7_defconfig. Enabling this Kconfig is causing the kernel to crash
on the Tegra20 Ventana platform in the ulpi_match() function.

The Qualcomm USB HS PHY driver that is enabled by CONFIG_PHY_QCOM_USB_HS,
registers a ulpi_driver but this driver does not provide an 'id_table',
so when ulpi_match() is called on the Tegra20 Ventana platform, it
crashes when attempting to deference the id_table pointer which is not
valid. The Qualcomm USB HS PHY driver uses device-tree for matching the
ULPI driver with the device and so fix this crash by using device-tree
for matching if the id_table is not valid.

Fixes: ef6a7bcfb01c ("usb: ulpi: Support device discovery via DT")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20220117150039.44058-1-jonathanh@nvidia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c
index 4169cf4..8f8405b 100644 (file)
--- a/drivers/usb/common/ulpi.c
+++ b/drivers/usb/common/ulpi.c
@@ -39,8 +39,11 @@ static int ulpi_match(struct device *dev, struct device_driver *driver)
        struct ulpi *ulpi = to_ulpi_dev(dev);
        const struct ulpi_device_id *id;
 
-       /* Some ULPI devices don't have a vendor id so rely on OF match */
-       if (ulpi->id.vendor == 0)
+       /*
+        * Some ULPI devices don't have a vendor id
+        * or provide an id_table so rely on OF match.
+        */
+       if (ulpi->id.vendor == 0 || !drv->id_table)
                return of_driver_match_device(dev, driver);
 
        for (id = drv->id_table; id->vendor; id++)