Re: [PATCH] usb: dwc3: gadget: Fix failure to detect end of transfer

[Bryan O'Donoghue]

On 30/12/2019 18:57, Greg KH wrote:
> On Mon, Dec 30, 2019 at 04:13:21PM +0000, Bryan O'Donoghue wrote:
> > A recent bugfix 8c7d4b7b3d43 ("usb: dwc3: gadget: Fix logical condition")
> > correctly fixes a logical error in the gadget driver but, exposes a further
> > bug in determining when a transfer has completed.
> >
> > Prior to 8c7d4b7b3d43 we were calling dwc3_gadget_giveback() when we
> > shouldn't have been. Afer this change the below test fails to complete on
> > my hardware.
> >
> > Host:
> > echo "host" > /dev/ttyACM0
> >
> > Device:
> > cat < /dev/ttyGS0
> >
> > This is caused by the driver incorrectly detecting end of transfer, a
> > problem that had previous been masked by the continuous calling of
> > dwc3_gadget_giveback() prior to 8c7d4b7b3d43.
> >
> > Remediate by making the test <= instead of ==
> >
> > Fixes: e0c42ce590fe ("usb: dwc3: gadget: simplify IOC handling")
> >
> > Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
> > ---
> >   drivers/usb/dwc3/gadget.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
>
> I think this patch:
> 	https://lore.kernel.org/linux-usb/ac5a3593a94fdaa3d92e6352356b5f7a01ccdc7c.1576291140.git.thinhn@xxxxxxxxxxxx/
>
> should fix this issue instead, right?
>
> If not, do I need to include both of these?

Yep, works fine in isolation.