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usb: dwc3: EP clear halt leading to clearing of delayed_status

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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>
This commit is contained in:
Wesley Cheng 2022-04-14 00:39:02 -07:00 committed by Greg Kroah-Hartman
parent 0f01017191
commit 2840d6dfcf
3 changed files with 7 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
drivers/usb/dwc3/core.h
View file

@ -1046,6 +1046,7 @@ struct dwc3_scratchpad_array {
* @tx_thr_num_pkt_prd: periodic ESS transmit packet count
* @tx_max_burst_prd: max periodic ESS transmit burst size
* @tx_fifo_resize_max_num: max number of fifos allocated during txfifo resize
* @clear_stall_protocol: endpoint number that requires a delayed status phase
* @hsphy_interface: "utmi" or "ulpi"
* @connected: true when we're connected to a host, false otherwise
* @softconnect: true when gadget connect is called, false when disconnect runs
@ -1266,6 +1267,7 @@ struct dwc3 {
u8 tx_thr_num_pkt_prd;
u8 tx_max_burst_prd;
u8 tx_fifo_resize_max_num;
u8 clear_stall_protocol;
const char *hsphy_interface;

1
drivers/usb/dwc3/ep0.c
View file

@ -1080,6 +1080,7 @@ void dwc3_ep0_send_delayed_status(struct dwc3 *dwc)
unsigned int direction = !dwc->ep0_expect_in;
dwc->delayed_status = false;
dwc->clear_stall_protocol = 0;
if (dwc->ep0state != EP0_STATUS_PHASE)
return;

5
drivers/usb/dwc3/gadget.c
View file

@ -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);
}