Re: [PULL 13/25] hcd-ohci: Fix inconsistency when resetting ohci root hubs

[Qiang Liu]

Hi,

I will take over this and fix it

Best,

Qiang

On Tue, Sep 27, 2022 at 9:11 AM Stefan Hajnoczi <stefanha@gmail.com> wrote:

On Mon, 26 Sept 2022 at 06:29, Gerd Hoffmann <kraxel@redhat.com> wrote:
>
> From: Qiang Liu <cyruscyliu@gmail.com>
>
> I found an assertion failure in usb_cancel_packet() and posted my analysis in
> https://gitlab.com/qemu-project/qemu/-/issues/1180. I think this issue is
> because the inconsistency when resetting ohci root hubs.
>
> There are two ways to reset ohci root hubs: 1) through HcRhPortStatus, 2)
> through HcControl. However, when the packet's status is USB_PACKET_ASYNC,
> resetting through HcRhPortStatus will complete the packet and thus resetting
> through HcControl will fail. That is because IMO resetting through
> HcRhPortStatus should first detach the port and then invoked usb_device_reset()
> just like through HcControl. Therefore, I change usb_device_reset() to
> usb_port_reset() where usb_detach() and usb_device_reset() are invoked
> consequently.
>
> Fixes: d28f4e2d8631 ("usb: kill USB_MSG_RESET")
> Reported-by: Qiang Liu <cyruscyliu@gmail.com>
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1180
> Signed-off-by: Qiang Liu <cyruscyliu@gmail.com>
> Message-Id: <20220830033022.1164961-1-cyruscyliu@gmail.com>
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  hw/usb/hcd-ohci.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

This commit breaks boot-serial-test on ppc64-softmmu.

  $ ./configure --enable-tcg-interpreter
'--target-list=aarch64-softmmu alpha-softmmu arm-softmmu hppa-softmmu
m68k-softmmu microblaze-softmmu ppc64-softmmu s390x-softmmu
x86_64-softmmu'
  $ make && cd build && QTEST_QEMU_BINARY=./qemu-system-ppc64
./tests/qtest/boot-serial-test; cd -

(Yes, the full --target-list is needed because boot-serial-test isn't
built when only ppc64-softmmu is selected.)

Here is the CI failure:
https://gitlab.com/qemu-project/qemu/-/jobs/3087540972#L22

Stefan

>
> diff --git a/hw/usb/hcd-ohci.c b/hw/usb/hcd-ohci.c
> index 72bdde92617c..28d703481515 100644
> --- a/hw/usb/hcd-ohci.c
> +++ b/hw/usb/hcd-ohci.c
> @@ -1436,7 +1436,7 @@ static void ohci_port_set_status(OHCIState *ohci, int portnum, uint32_t val)
>
>      if (ohci_port_set_if_connected(ohci, portnum, val & OHCI_PORT_PRS)) {
>          trace_usb_ohci_port_reset(portnum);
> -        usb_device_reset(port->port.dev);
> +        usb_port_reset(&port->port);
>          port->ctrl &= ~OHCI_PORT_PRS;
>          /* ??? Should this also set OHCI_PORT_PESC.  */
>          port->ctrl |= OHCI_PORT_PES | OHCI_PORT_PRSC;
> --
> 2.37.3
>
>