From c5f14abeb52b0177b940fd734133d383da3521d8 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Thu, 4 Aug 2022 17:09:58 +0200 Subject: [PATCH] usb: dwc3: qcom: fix peripheral and OTG suspend A recent commit implementing wakeup support in host mode instead broke suspend for peripheral and OTG mode. The hack that was added in the suspend path to determine the speed of any device connected to the USB2 bus not only accesses internal driver data for a child device, but also dereferences a NULL pointer or accesses freed data when the controller is not acting as host. There's no quick fix to the layering violation, but since reverting would leave us with broken suspend in host mode with wakeup triggering immediately, let's keep the hack for now. Fix the immediate issues by only checking the host bus speed and enabling wakeup interrupts when acting as host. Fixes: 6895ea55c385 ("usb: dwc3: qcom: Configure wakeup interrupts during suspend") Reported-by: kernel test robot Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20220804151001.23612-7-johan+linaro@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/usb/dwc3/dwc3-qcom.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c index 05b4666..6ae0b7f 100644 --- a/drivers/usb/dwc3/dwc3-qcom.c +++ b/drivers/usb/dwc3/dwc3-qcom.c @@ -309,8 +309,13 @@ static bool dwc3_qcom_is_host(struct dwc3_qcom *qcom) static enum usb_device_speed dwc3_qcom_read_usb2_speed(struct dwc3_qcom *qcom) { struct dwc3 *dwc = platform_get_drvdata(qcom->dwc3); - struct usb_hcd *hcd = platform_get_drvdata(dwc->xhci); struct usb_device *udev; + struct usb_hcd *hcd; + + /* + * FIXME: Fix this layering violation. + */ + hcd = platform_get_drvdata(dwc->xhci); /* * It is possible to query the speed of all children of @@ -416,7 +421,11 @@ static int dwc3_qcom_suspend(struct dwc3_qcom *qcom, bool wakeup) if (ret) dev_warn(qcom->dev, "failed to disable interconnect: %d\n", ret); - if (wakeup) { + /* + * The role is stable during suspend as role switching is done from a + * freezable workqueue. + */ + if (dwc3_qcom_is_host(qcom) && wakeup) { qcom->usb2_speed = dwc3_qcom_read_usb2_speed(qcom); dwc3_qcom_enable_interrupts(qcom); } @@ -434,7 +443,7 @@ static int dwc3_qcom_resume(struct dwc3_qcom *qcom, bool wakeup) if (!qcom->is_suspended) return 0; - if (wakeup) + if (dwc3_qcom_is_host(qcom) && wakeup) dwc3_qcom_disable_interrupts(qcom); for (i = 0; i < qcom->num_clocks; i++) { -- 2.7.4