On Wednesday, September 09, 2015 at 06:30:20 AM, Peng Fan wrote:
Hi Marek,
Hi!
On Wed, Sep 09, 2015 at 11:24:37AM +0800, Peng Fan wrote:
On Tue, Sep 08, 2015 at 07:17:22PM -0700, Stephen Warren wrote:
On 09/03/2015 03:11 PM, Marek Vasut wrote:
On Tuesday, September 01, 2015 at 09:45:12 PM, Stephen Warren wrote:
On 08/30/2015 12:26 AM, Peng Fan wrote:
Hi Stephen,
Hi,
sorry for the delayed reply, I had to dig into the code myself.
On Fri, Aug 28, 2015 at 08:05:36AM +0800, Peng Fan wrote: > Hi Stephen, > > On Thu, Aug 27, 2015 at 10:06:14AM -0600, Stephen Warren wrote: >> On 08/27/2015 05:08 AM, Marek Vasut wrote: >>> On Thursday, August 27, 2015 at 01:00:50 PM, Peng Fan wrote: >>>> Implement endpoint dequeue callback function. >>>> >>>> Without this function, uboot will hang when executing fastboot >>>> comamnd. See following flow: >>>> "fastboot_tx_write_str->fastboot_tx_write->usb_ep_dequeue->ep->op >>>> s->d equeue " without implement ci_udc dequeue function, >>>> ep->ops->dequeue is NULL, then uboot will hang. >>>> >>>> Tested on mx6qsabresd board with fastboot enabled. >>>> >>>> diff --git a/drivers/usb/gadget/ci_udc.c >>>> b/drivers/usb/gadget/ci_udc.c >>>> >>>> +static int ci_ep_dequeue(struct usb_ep *_ep, struct usb_request >>>> *_req) >>>> >>>> + if (ci_req->req.status == -EINPROGRESS) { >>>> + ci_req->req.status = -ECONNRESET; >>>> + if (ci_req->req.complete) >>>> + ci_req->req.complete(_ep, _req); >>>> + } >> >> Is there no need to reprogram the HW to abort the transfer? > > I checked linux udc driver drivers/usb/gadget/udc/fsl_qe_udc.c > qe_ep_dequeue->done->usb_gadget_giveback_request->"req->complete(ep, > req)" I did not see code to reprogram the HW to abort the transfer.
Do you have further comments? I checked other gadget drivers in drivers/usb/gadget/, I did not see drivers that reprogram the HW to abort the transfer. For now, I do not think out a scenario to reprogram the HW to abort the transfer
Marek, what are the semantics of this function? Is it supposed to simply update SW state to make U-Boot not care about the transaction
Yes, that's correct.
or is it supposed to actually stop the HW performing the transaction on the USB bus?
No, it's not supposed to kill the transaction in hardware.
OK, the patch seems fine then.
If it's the former, then the patch is likely fine. If it's the latter, then I think the function does need actually need to do something to make the HW stop, or we can't implement this particular function.
Do we need this for the current release or is this for -next ?
I assume that's a question for Peng?
Since this is a bug fix, I think this patch should be in current release. Without this patch, boards which want to enable fastboot using ci_udc driver will hang.
If you have plan to pick the bug fix, please pick V2. https://patchwork.ozlabs.org/patch/511739/
Aye aye, sir! One applied patch, coming right up!