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| author | Wesley Cheng <quic_wcheng@quicinc.com> | 2022-04-14 00:39:02 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-23 10:33:52 +0200 |
| commit | 2840d6dfcf4306878f7d17ac16d4a0a6422728cc (patch) | |
| tree | 1b5d43e3817702576e1af787ae99c7c3aac2dfeb /drivers/usb/dwc3/gadget.c | |
| parent | 0f01017191384e3962fa31520a9fd9846c3d352f (diff) | |
| download | linux-2840d6dfcf4306878f7d17ac16d4a0a6422728cc.tar.gz linux-2840d6dfcf4306878f7d17ac16d4a0a6422728cc.tar.bz2 linux-2840d6dfcf4306878f7d17ac16d4a0a6422728cc.zip | |
usb: dwc3: EP clear halt leading to clearing of delayed_status
The usb_ep_clear_halt() API can be called from the function driver, and
translates to dwc3_gadget_ep_set_halt(). This routine is shared with when
the host issues a clear feature ENDPOINT_HALT, and is differentiated by the
protocol argument. If the following sequence occurs, there can be a
situation where the delayed_status flag is improperly cleared for the wrong
SETUP transaction:
1. Vendor specific control transfer returns USB_GADGET_DELAYED_STATUS.
2. DWC3 gadget sets dwc->delayed_status to '1'.
3. Another function driver issues a usb_ep_clear_halt() call.
4. DWC3 gadget issues dwc3_stop_active_transfer() and sets
DWC3_EP_PENDING_CLEAR_STALL.
5. EP command complete interrupt triggers for the end transfer, and
dwc3_ep0_send_delayed_status() is allowed to run, as delayed_status
is '1' due to step#1.
6. STATUS phase is sent, and delayed_status is cleared.
7. Vendor specific control transfer is finished being handled, and issues
usb_composite_setup_continue(). This results in queuing of a data
phase.
Cache the protocol flag so that DWC3 gadget is aware of when the clear halt
is due to a SETUP request from the host versus when it is sourced from a
function driver. This allows for the EP command complete interrupt to know
if it needs to issue a delayed status phase.
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
Link: https://lore.kernel.org/r/20220414073902.21960-1-quic_wcheng@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/dwc3/gadget.c')
| -rw-r--r-- | drivers/usb/dwc3/gadget.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index c3d95f9b010b..efaa63df9336 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -2152,6 +2152,9 @@ int __dwc3_gadget_ep_set_halt(struct dwc3_ep *dep, int value, int protocol) if (dep->flags & DWC3_EP_END_TRANSFER_PENDING || (dep->flags & DWC3_EP_DELAY_STOP)) { dep->flags |= DWC3_EP_PENDING_CLEAR_STALL; + if (protocol) + dwc->clear_stall_protocol = dep->number; + return 0; } @@ -3483,7 +3486,7 @@ static void dwc3_gadget_endpoint_command_complete(struct dwc3_ep *dep, } dep->flags &= ~(DWC3_EP_STALL | DWC3_EP_WEDGE); - if (dwc->delayed_status) + if (dwc->clear_stall_protocol == dep->number) dwc3_ep0_send_delayed_status(dwc); } |