> On Fri, Feb 22, 2019 at 10:53:19AM +0100, Lorenzo Bianconi wrote:
> > > Use usb_bulk_msg for reading MCU command responses. This simplify code
> > > a lot.
> > >
> > > Together with 97a3005759c ("mt76usb: allow mt76u_bulk_msg be used
> > > for reads") it also fix possible problems with rx data buffers
> > > not being aligned and contained within single page. After doing
> > > page_frag_alloc(1024) consecutive page_frag_alloc(PAGE_SIZE) will
> > > alloc PAGE_SIZE buffer at PAGE_SIZE - 1024 offset.
> > >
> > > Signed-off-by: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>
> > > ---
> > > drivers/net/wireless/mediatek/mt76/mt76.h | 3 +-
> > > drivers/net/wireless/mediatek/mt76/mt76x0/usb.c | 11 --------
> > > .../net/wireless/mediatek/mt76/mt76x02_usb_mcu.c | 32 +++++++---------------
> > > drivers/net/wireless/mediatek/mt76/mt76x2/usb.c | 11 --------
> > > drivers/net/wireless/mediatek/mt76/usb.c | 1 -
> > > drivers/net/wireless/mediatek/mt76/usb_mcu.c | 31 +++------------------
> > > 6 files changed, 15 insertions(+), 74 deletions(-)
> > >
> > > diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h
> > > index 6092646014c4..c9b5eb9b0582 100644
> > > --- a/drivers/net/wireless/mediatek/mt76/mt76.h
> > > +++ b/drivers/net/wireless/mediatek/mt76/mt76.h
> > > @@ -384,8 +384,7 @@ struct mt76_usb {
> > >
> > > struct mt76u_mcu {
> > > struct mutex mutex;
> > > - struct completion cmpl;
> >
> > Hi Stanislaw,
> >
> > I was reviewing this approach and I guess it is a little bit racey since now we
> > are not sure that when the device is removed or suspended the pending mcu commands
> > are terminated and we do not have any api to stop usb transactions.
> > Are we sure when we access mt76x02_dev/mt76_dev structure it has not been
> > already removed?
> > Maybe we need to maintain the completion in mt76u_mcu and use it to wait the mcu
> > commands are terminated.
>
> I don't think so. On suspend we do mt76xxu_mac_stop() which access registers
> using mcu commands, all should be synchronized by mcu->mutex . All other
> process that could use mcu command should be already stopped. Actually suspend
> can be simplified.
ack, I missed mcu->mutex. Thx.
Regards,
Lorenzo
>
> Device remove should be properly handled by -ENODEV error returned by
> usb_bulk_msg.
>
> Stanislaw
