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[PATCH] hw/usb/hcd-dwc2: Enforce epnum to 0 for the control endpoint to
From: |
Qiang Liu |
Subject: |
[PATCH] hw/usb/hcd-dwc2: Enforce epnum to 0 for the control endpoint to avoid the assertion failure in usb_ep_get() |
Date: |
Sun, 27 Jun 2021 11:28:26 +0800 |
When eptype is USB_ENDPOINT_XFER_CONTROL and pid is
TSIZ_SC_MC_PID_SETUP, usb_ep_get() should return the control endpoint.
In hw/usb/core.c, the assumed epnum of the control endpoint is 0. When
epnum is not 0, usb_ep_get() will crash due to the check assert(pid ==
USB_TOKEN_IN || pid == USB_TOKEN_OUT).
The description
http://www.capital-micro.com/PDF/CME-M7_Family_User_Guide_EN.pdf
(18.5.3.4 (14), 18.5.3.4 (10)) a) mentions that the pid is maintained by
the host, b) but doesn't mention that whether the epnum should be 0 for
the control endpoint. However, usb_ep_get() assumes it is 0. To avoid
potential assertion failure in usb_ep_get(), we could enforce epnum to 0
and warn users.
Fixes: 153ef1662c3 ("dwc-hsotg (dwc2) USB host controller emulation")
Signed-off-by: Qiang Liu <cyruscyliu@gmail.com>
---
hw/usb/hcd-dwc2.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/hw/usb/hcd-dwc2.c b/hw/usb/hcd-dwc2.c
index e1d96ac..65d9d46 100644
--- a/hw/usb/hcd-dwc2.c
+++ b/hw/usb/hcd-dwc2.c
@@ -636,6 +636,11 @@ static void dwc2_enable_chan(DWC2State *s, uint32_t index)
}
if (eptype == USB_ENDPOINT_XFER_CONTROL && pid == TSIZ_SC_MC_PID_SETUP) {
+ if (epnum != 0) {
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "epnum should be 0 for the control endpoint\n");
+ epnum = 0;
+ }
pid = USB_TOKEN_SETUP;
} else {
pid = epdir ? USB_TOKEN_IN : USB_TOKEN_OUT;
--
2.7.4
- [PATCH] hw/usb/hcd-dwc2: Enforce epnum to 0 for the control endpoint to avoid the assertion failure in usb_ep_get(),
Qiang Liu <=