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Date:   Sat, 3 Apr 2021 07:57:26 +0800
From:   Peter Chen <peter.chen@kernel.org>
To:     Pawel Laszczak <pawell@cadence.com>
Cc:     "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Rahul Kumar <kurahul@cadence.com>
Subject: Re: [PATCH] usb: cdnsp: Fixes issue with Configure Endpoint command
Message-ID: <20210402235726.GA18389@b29397-desktop>
References: <20210322060902.11197-1-pawell@gli-login.cadence.com>
 <20210327005417.GB28870@b29397-desktop>
 <BYAPR07MB53814609AA96C16D6432761DDD7D9@BYAPR07MB5381.namprd07.prod.outlook.com>
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On 21-03-30 04:26:10, Pawel Laszczak wrote:
> Hi Peter,
> 
> >
> >On 21-03-22 07:09:02, Pawel Laszczak wrote:
> >> From: Pawel Laszczak <pawell@cadence.com>
> >>
> >> Patch adds flag EP_UNCONFIGURED to detect whether endpoint was
> >> unconfigured. This flag is set in cdnsp_reset_device after Reset Device
> >> command. Among others this command disables all non control endpoints.
> >> Flag is used in cdnsp_gadget_ep_disable to protect controller against
> >> invoking Configure Endpoint command on disabled endpoint. Lack of this
> >> protection in some cases caused that Configure Endpoint command completed
> >> with Context State Error code completion.
> >>
> >> Fixes: 3d82904559f4 ("usb: cdnsp: cdns3 Add main part of Cadence USBSSP DRD Driver")
> >> Signed-off-by: Pawel Laszczak <pawell@cadence.com>
> >> ---
> >>  drivers/usb/cdns3/cdnsp-gadget.c | 18 +++++++++++++-----
> >>  drivers/usb/cdns3/cdnsp-gadget.h | 11 ++++++-----
> >>  2 files changed, 19 insertions(+), 10 deletions(-)
> >>
> >> diff --git a/drivers/usb/cdns3/cdnsp-gadget.c b/drivers/usb/cdns3/cdnsp-gadget.c
> >> index d7d4bdd57f46..de17cc4ad91a 100644
> >> --- a/drivers/usb/cdns3/cdnsp-gadget.c
> >> +++ b/drivers/usb/cdns3/cdnsp-gadget.c
> >> @@ -727,7 +727,7 @@ int cdnsp_reset_device(struct cdnsp_device *pdev)
> >>  	 * are in Disabled state.
> >>  	 */
> >>  	for (i = 1; i < CDNSP_ENDPOINTS_NUM; ++i)
> >> -		pdev->eps[i].ep_state |= EP_STOPPED;
> >> +		pdev->eps[i].ep_state |= EP_STOPPED | EP_UNCONFIGURED;
> >>
> >>  	trace_cdnsp_handle_cmd_reset_dev(slot_ctx);
> >>
> >> @@ -942,6 +942,7 @@ static int cdnsp_gadget_ep_enable(struct usb_ep *ep,
> >>
> >>  	pep = to_cdnsp_ep(ep);
> >>  	pdev = pep->pdev;
> >> +	pep->ep_state &= ~EP_UNCONFIGURED;
> >>
> >>  	if (dev_WARN_ONCE(pdev->dev, pep->ep_state & EP_ENABLED,
> >>  			  "%s is already enabled\n", pep->name))
> >> @@ -1023,9 +1024,13 @@ static int cdnsp_gadget_ep_disable(struct usb_ep *ep)
> >>  		goto finish;
> >>  	}
> >>
> >> -	cdnsp_cmd_stop_ep(pdev, pep);
> >>  	pep->ep_state |= EP_DIS_IN_RROGRESS;
> >> -	cdnsp_cmd_flush_ep(pdev, pep);
> >> +
> >> +	/* Endpoint was unconfigured by Reset Device command. */
> >> +	if (!(pep->ep_state & EP_UNCONFIGURED)) {
> >> +		cdnsp_cmd_stop_ep(pdev, pep);
> >> +		cdnsp_cmd_flush_ep(pdev, pep);
> >> +	}
> >>
> >>  	/* Remove all queued USB requests. */
> >>  	while (!list_empty(&pep->pending_list)) {
> >> @@ -1036,6 +1041,7 @@ static int cdnsp_gadget_ep_disable(struct usb_ep *ep)
> >>  	cdnsp_invalidate_ep_events(pdev, pep);
> >>
> >>  	pep->ep_state &= ~EP_DIS_IN_RROGRESS;
> >> +
> >
> >Useless blank line
> >
> >>  	drop_flag = cdnsp_get_endpoint_flag(pep->endpoint.desc);
> >>  	ctrl_ctx = cdnsp_get_input_control_ctx(&pdev->in_ctx);
> >>  	ctrl_ctx->drop_flags = cpu_to_le32(drop_flag);
> >> @@ -1043,10 +1049,12 @@ static int cdnsp_gadget_ep_disable(struct usb_ep *ep)
> >>
> >>  	cdnsp_endpoint_zero(pdev, pep);
> >>
> >> -	ret = cdnsp_update_eps_configuration(pdev, pep);
> >> +	if (!(pep->ep_state & EP_UNCONFIGURED))
> >> +		ret = cdnsp_update_eps_configuration(pdev, pep);
> >> +
> >>  	cdnsp_free_endpoint_rings(pdev, pep);
> >>
> >> -	pep->ep_state &= ~EP_ENABLED;
> >> +	pep->ep_state &= ~(EP_ENABLED | EP_UNCONFIGURED);
> >>  	pep->ep_state |= EP_STOPPED;
> >>
> >>  finish:
> >> diff --git a/drivers/usb/cdns3/cdnsp-gadget.h b/drivers/usb/cdns3/cdnsp-gadget.h
> >> index 6bbb26548c04..e628bd539e23 100644
> >> --- a/drivers/usb/cdns3/cdnsp-gadget.h
> >> +++ b/drivers/usb/cdns3/cdnsp-gadget.h
> >> @@ -830,11 +830,12 @@ struct cdnsp_ep {
> >>  	unsigned int ep_state;
> >>  #define EP_ENABLED		BIT(0)
> >>  #define EP_DIS_IN_RROGRESS	BIT(1)
> >> -#define EP_HALTED		BIT(2)
> >> -#define EP_STOPPED		BIT(3)
> >> -#define EP_WEDGE		BIT(4)
> >> -#define EP0_HALTED_STATUS	BIT(5)
> >> -#define EP_HAS_STREAMS		BIT(6)
> >> +#define EP_UNCONFIGURED		BIT(2)
> >
> >Why add new flag as BIT(2), it causes many changes in this patch?
> 
> In my feeling, EP_UNCONFIGURED is more associates with the first 2 flags, so I've decided 
> put it after BIT(1).  

No, you may not add such relationship, each flag has its own meaning,
otherwise, the sequence of flag bitmap may be changed again.

Peter

> 
> >
> >> +#define EP_HALTED		BIT(3)
> >> +#define EP_STOPPED		BIT(4)
> >> +#define EP_WEDGE		BIT(5)
> >> +#define EP0_HALTED_STATUS	BIT(6)
> >> +#define EP_HAS_STREAMS		BIT(7)
> >>
> >>  	bool skip;
> >>  };
> >> --
> >> 2.25.1
> >>
> >
> >--
> >
> >Thanks,
> >Peter Chen
> 

-- 

Thanks,
Peter Chen