From: Fabio Estevam <fabio.estevam@xxxxxxx>
Commit e93650994a95 ("usb: phy: mxs: add usb charger type detection")
causes the following kernel hang on i.MX28:
[ 2.207973] usbcore: registered new interface driver usb-storage
[ 2.235659] Unable to handle kernel NULL pointer dereference at virtual address 00000188
[ 2.244195] pgd = (ptrval)
[ 2.246994] [00000188] *pgd=00000000
[ 2.250676] Internal error: Oops: 5 [#1] ARM
[ 2.254979] Modules linked in:
[ 2.258089] CPU: 0 PID: 1 Comm: swapper Not tainted 4.15.0-rc8-next-20180117-00002-g75d5f21 #7
[ 2.266724] Hardware name: Freescale MXS (Device Tree)
[ 2.271921] PC is at regmap_read+0x0/0x5c
[ 2.275977] LR is at mxs_phy_charger_detect+0x34/0x1dc
mxs_phy_charger_detect() makes accesses to the anatop registers via regmap,
however i.MX23/28 do not have such registers, which causes a NULL pointer
dereference.
Fix the issue by doing a NULL check on the 'regmap' pointer.
Fixes: e93650994a95 ("usb: phy: mxs: add usb charger type detection")
Signed-off-by: Fabio Estevam <fabio.estevam@xxxxxxx>
---
Changes since v1:
- Perform a NULL check on regmap (Jun Li)
drivers/usb/phy/phy-mxs-usb.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/usb/phy/phy-mxs-usb.c b/drivers/usb/phy/phy-mxs-usb.c
index da031c4..4e2eb9d 100644
--- a/drivers/usb/phy/phy-mxs-usb.c
+++ b/drivers/usb/phy/phy-mxs-usb.c
@@ -602,6 +602,9 @@ static enum usb_charger_type mxs_phy_charger_detect(struct usb_phy *phy)
void __iomem *base = phy->io_priv;
enum usb_charger_type chgr_type = UNKNOWN_TYPE;
+ if (!regmap)
+ return UNKNOWN_TYPE;
+
if (mxs_charger_data_contact_detect(mxs_phy))
return chgr_type;
--
2.7.4
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