On Wed, Feb 20, 2019 at 05:27:02PM +0100, Thierry Reding wrote: > On Wed, Feb 20, 2019 at 05:16:12PM +0100, Greg Kroah-Hartman wrote: > > On Wed, Feb 20, 2019 at 02:48:41PM +0100, Thierry Reding wrote: > > > From: Thierry Reding <treding@xxxxxxxxxx> > > > > > > During initialization, the host and super-speed power domains will > > > contain an ERR_PTR() encoded error code rather than being NULL. To > > > avoid a crash, use a !IS_ERR_OR_NULL() condition during cleanup. > > > > > > Signed-off-by: Thierry Reding <treding@xxxxxxxxxx> > > > --- > > > drivers/usb/host/xhci-tegra.c | 4 ++-- > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/usb/host/xhci-tegra.c b/drivers/usb/host/xhci-tegra.c > > > index 938ff06c0349..efb0cad8710e 100644 > > > --- a/drivers/usb/host/xhci-tegra.c > > > +++ b/drivers/usb/host/xhci-tegra.c > > > @@ -941,9 +941,9 @@ static void tegra_xusb_powerdomain_remove(struct device *dev, > > > device_link_del(tegra->genpd_dl_ss); > > > if (tegra->genpd_dl_host) > > > device_link_del(tegra->genpd_dl_host); > > > - if (tegra->genpd_dev_ss) > > > + if (!IS_ERR_OR_NULL(tegra->genpd_dev_ss)) > > > dev_pm_domain_detach(tegra->genpd_dev_ss, true); > > > - if (tegra->genpd_dev_host) > > > + if (!IS_ERR_OR_NULL(tegra->genpd_dev_host)) > > > dev_pm_domain_detach(tegra->genpd_dev_host, true); > > > } > > > > Should this go to older kernels? If so, any hint as to what commit this > > "fixes:"? > > Technically this: > > Fixes: 6494a9ad86de ("usb: xhci: tegra: Add genpd support") > > which was merged into v4.20. > > However, I have never seen this actually crash on current kernels and > only came across it while working on a change to reset controls which > can cause dev_pm_domain_attach_by_name() to fail. That function can't > fail in current kernels, so I don't think we need to fix this in old > kernels. So if we can get this into v5.0, that'd be good enough for > me. 5.0-final is too late, but 5.0.y is doable. Mathias, want me to take this directly? thanks, greg k-h