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SubjectRe: [PATCH v5 0/3] Avoid having pending end transfers on soft disconnect
On Thu, Apr 13, 2023 at 12:57:39PM -0700, Wesley Cheng wrote:
> In case there is a host which takes time to complete a SETUP transaction,
> during the soft disconnect sequence multiple DWC3 EPs will have their
> DWC3_EP_DELAY_STOP flag set w/o issuing the end transfer command. Once the
> controller halt sequence occurs, the soft disconnect is successful, and
> the subsequent soft connect will attempt to flush the pending end transfers.
>
> Soft disconnect sequence:
> dwc3_gadget_ep_disable name=ep8in flags=0x3009 direction=1
> dwc3_gadget_ep_disable name=ep4in flags=1 direction=1
> dwc3_gadget_ep_disable name=ep3out flags=1 direction=0
> usb_gadget_disconnect deactivated=0 connected=0 ret=0
>
> Soft connect bug:
> BUG: spinlock already unlocked on CPU
> spin_bug+0x0
> dwc3_remove_requests+0x278
> dwc3_ep0_out_start+0xb0
> __dwc3_gadget_start+0x25c
>
> The bug occurs due to the flush of the pending end transfers, as the gadget
> start routine is not held with a spinlock. However, if the DWC3_EP_DELAY_STOP
> is set, it will call the giveback API, which attempts to unlock the dwc->lock.
> Ideally, the DWC3 gadget should not have pending end transfers on a soft
> connect, so fix this by:
>
> 1. Re-locating the SETUP phase check after stop active transfers, since
> that is where the DWC3_EP_DELAY_STOP is potentially set. This also allows
> for handling of a host that may be unresponsive by using the completion
> timeout to trigger the stall and restart for EP0.
>
> 2. Do not call gadget stop until the poll for controller halt is
> completed. DEVTEN is cleared as part of gadget stop, so the intention to
> allow ep0 events to continue while waiting for controller halt is not
> happening.

Only patch 1 applied, can you rebase the rest and resend with the acks
applied?

thanks,

greg k-h

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