From: Sergey Shtylyov s.shtylyov@omp.ru
stable inclusion from stable-v6.6.2 commit 72bb78c4048c99dca17c00073b650f7c5d2869a7 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8IW7G
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit a5f928db59519a15e82ecba4ae3e7cbf5a44715a ]
If this driver enables the xHC clocks while resuming from sleep, it calls clk_prepare_enable() without checking for errors and blithely goes on to read/write the xHC's registers -- which, with the xHC not being clocked, at least on ARM32 usually causes an imprecise external abort exceptions which cause kernel oops. Currently, the chips for which the driver does the clock dance on suspend/resume seem to be the Broadcom STB SoCs, based on ARM32 CPUs, as it seems...
Found by Linux Verification Center (linuxtesting.org) with the Svace static analysis tool.
Fixes: 8bd954c56197 ("usb: host: xhci-plat: suspend and resume clocks") Signed-off-by: Sergey Shtylyov s.shtylyov@omp.ru Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com Link: https://lore.kernel.org/r/20231019102924.2797346-19-mathias.nyman@linux.inte... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- drivers/usb/host/xhci-plat.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c index 28218c8f1837..b93161374293 100644 --- a/drivers/usb/host/xhci-plat.c +++ b/drivers/usb/host/xhci-plat.c @@ -458,23 +458,38 @@ static int __maybe_unused xhci_plat_resume(struct device *dev) int ret;
if (!device_may_wakeup(dev) && (xhci->quirks & XHCI_SUSPEND_RESUME_CLKS)) { - clk_prepare_enable(xhci->clk); - clk_prepare_enable(xhci->reg_clk); + ret = clk_prepare_enable(xhci->clk); + if (ret) + return ret; + + ret = clk_prepare_enable(xhci->reg_clk); + if (ret) { + clk_disable_unprepare(xhci->clk); + return ret; + } }
ret = xhci_priv_resume_quirk(hcd); if (ret) - return ret; + goto disable_clks;
ret = xhci_resume(xhci, PMSG_RESUME); if (ret) - return ret; + goto disable_clks;
pm_runtime_disable(dev); pm_runtime_set_active(dev); pm_runtime_enable(dev);
return 0; + +disable_clks: + if (!device_may_wakeup(dev) && (xhci->quirks & XHCI_SUSPEND_RESUME_CLKS)) { + clk_disable_unprepare(xhci->clk); + clk_disable_unprepare(xhci->reg_clk); + } + + return ret; }
static int __maybe_unused xhci_plat_runtime_suspend(struct device *dev)