On Fri, Nov 15, 2024 at 02:45:45PM +0530, Krishna Kurapati wrote: > Commit [1] introduced DP support to QMP driver. While doing so, the > dp and usb configuration structures were added to a combo_phy_cfg > structure. During probe, the match data is used to parse and identify the > dp and usb configs separately. While doing so, the usb_cfg variable > represents the configuration parameters for USB part of the phy (whether > it is DP-Cobo or Uni). during probe, one corner case of parsing usb_cfg > for Uni PHYs is left incomplete and it is left as NULL. This NULL variable > further percolates down to qmp_phy_create() call essentially getting > de-referenced and causing a crash. The UNI PHY platforms don't have usb3-phy subnode. As such the usb_cfg variable should not be used in the for_each_available_child_of_node() loop. Please provide details for the platform on which you observe the crash and the backtrace. > > Subsequently, commit [2] split the driver into multiple files, each > handling a specific PHY type (USB, DP-Combo, UFS, PCIe). During this > refactoring, the probing process was modified, and the NULL pointer > dereference issue no longer showed up. > > [1]: https://lore.kernel.org/all/20200916231202.3637932-8-swboyd@xxxxxxxxxxxx/ > [2]: https://lore.kernel.org/all/20220607213203.2819885-1-dmitry.baryshkov@xxxxxxxxxx/ > > Fixes: 52e013d0bffa ("phy: qcom-qmp: Add support for DP in USB3+DP combo phy") > Cc: stable@xxxxxxxxxxxxxxx # 5.15.y > Signed-off-by: Krishna Kurapati <quic_kriskura@xxxxxxxxxxx> > --- > drivers/phy/qualcomm/phy-qcom-qmp.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c b/drivers/phy/qualcomm/phy-qcom-qmp.c > index eef863108bfe..e22ee71aa060 100644 > --- a/drivers/phy/qualcomm/phy-qcom-qmp.c > +++ b/drivers/phy/qualcomm/phy-qcom-qmp.c > @@ -5714,6 +5714,8 @@ static int qcom_qmp_phy_probe(struct platform_device *pdev) > > usb_cfg = combo_cfg->usb_cfg; > cfg = usb_cfg; /* Setup clks and regulators */ > + } else { > + usb_cfg = cfg; > } > > /* per PHY serdes; usually located at base address */ > -- > 2.34.1 > -- With best wishes Dmitry
