On 4.9.2020 13.01, Jun Li wrote: > > >> -----Original Message----- >> From: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx> >> Sent: Thursday, September 3, 2020 5:39 PM >> To: Jun Li <jun.li@xxxxxxx>; mathias.nyman@xxxxxxxxx >> Cc: gregkh@xxxxxxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx; dl-linux-imx >> <linux-imx@xxxxxxx> >> Subject: Re: [PATCH v2] usb: xhci: add debugfs support for ep with stream >> >> On 3.9.2020 10.46, Jun Li wrote: >>> >>>> -----Original Message----- >>>> From: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx> >>>> Sent: Thursday, September 3, 2020 3:24 PM >>>> To: Jun Li <jun.li@xxxxxxx>; mathias.nyman@xxxxxxxxx >>>> Cc: gregkh@xxxxxxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx; >>>> dl-linux-imx <linux-imx@xxxxxxx> >>>> Subject: Re: [PATCH v2] usb: xhci: add debugfs support for ep with >>>> stream >>>> >>>>>> I think this debugfs code is just called too early. It shouldn't >>>>>> need to check new_ring pointer at all. >>>>>> >>>>>> I wrote a fix that changes the order and makes sure endpoint is >>>>>> enabled and ring pointer is set correctly before we call >>>>>> xhci_debugfs_create_endpoint() >>>>>> >>>>>> https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fg >>>>>> it >>>>>> .kernel.o >>>>>> rg%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Fmnyman%2Fxhci.git%2Fcommit% >>>>>> 2F >>>>>> %3Fh%3Dfo >>>>>> r-usb-linus%26id%3Dcf99aef5624a592fd4f3374c7060bfa1a65f15df&dat >>>>>> a= >>>>>> 02%7C01%7 >>>>>> Cjun.li%40nxp.com%7C73e4663a6f6641fbb8b308d84f3d021a%7C686ea1d3bc2b >>>>>> 4c >>>>>> 6fa92cd99 >>>>>> c5c301635%7C0%7C0%7C637346470803922895&sdata=i4DfCW8EVUSAWnzb8Q >>>>>> l4 >>>>>> jPjAOD5wp >>>>>> tfbaMrO8vKvtDc%3D&reserved=0 >>>>> >>>>> This is a good place for non-zero Eps, but does not cover ep0. >>>>> >>>> >>>> ep0 is special, it's not touched in these add/drop endpoint or check >>>> bandwidth functions. >>>> >>>> ep0 ring is allocated earlier during slot creation in >>>> xhci_alloc_virt_device() >>>> ... >>>> /* Allocate endpoint 0 ring */ >>>> dev->eps[0].ring = xhci_ring_alloc(xhci, 2, 1, TYPE_CTRL, 0, >>>> flags); >>>> >>>> and for debugfs ep00 is added manually together with the slot >>>> xhci_debugfs_create_slot() >>>> ... >>>> xhci_debugfs_create_ring_dir(xhci, &dev->eps[0].ring, "ep00", >>>> priv->root); >>>> >>>> So regarding ep0 the change should be ok. >>> >>> Sorry, I forgot debugfs of ep0 is created via xhci_debugfs_create_slot(). >>> >>> Then I think your change is OK, also I gave a test with my stream/UAS >>> device on top of your patch and it can work fine. >>> >>> Do you need I post a new version of my patch(to remove touch of .new_ring)? >> >> If you could yes, and also change to a double pointer: >> >> struct xhci_ep_priv { >> ... >> + struct xhci_ring **show_ring; > > With current: struct xhci_ring *show_ring; > As I use one trb file to show different trb rings for one EP, so I need get > the addr of trb ring pointed by show_ring(which can be updated). > > If I change it to be **show_ring, then I am passing the addr of dev->eps[i].ring > to debugfs so I can't use show_ring's update value when show trb, makes me > not easy to get the addr of target trb ring. Right, ok, lets not use the douple pointer. We just have to trust epriv->show_ring is up to date. -Mathias
