Re: [PATCH v9 16/16] staging: r8188eu: remove usb_vendor_req_mutex

[Pavel Skripkin]

On 9/23/21 14:07, Greg KH wrote:
> On Thu, Sep 23, 2021 at 01:12:53PM +0300, Pavel Skripkin wrote:
> > On 9/23/21 11:47, Pavel Skripkin wrote:
> > > On 9/22/21 16:21, Pavel Skripkin wrote:
> > > > On 9/21/21 21:18, Fabio M. De Francesco wrote:
> > > > > From: Pavel Skripkin <paskripkin@xxxxxxxxx>
> > > > > 
> > > > > This mutex was used to protect shared buffer for USB requests. Since
> > > > > buffer was removed in previous patch we can remove this mutex as well.
> > > > > 
> > > > > Furthermore, because it was used to serialize the calls to the Core USB
> > > > > API, we thoroughly tested the enabling of concurrent firing of USB requests
> > > > > without the mutex and found no problems of any kind in common use cases.
> > > > > 
> > > > > Co-developed-by: Fabio M. De Francesco <fmdefrancesco@xxxxxxxxx>
> > > > > Signed-off-by: Fabio M. De Francesco <fmdefrancesco@xxxxxxxxx>
> > > > > Signed-off-by: Pavel Skripkin <paskripkin@xxxxxxxxx>
> > > > 
> > > > Hi, Greg!
> > > > 
> > > > If all is OK with previous 15 patches, please, do not take this one, it
> > > >    causes problems with connection... :)
> > > > 
> > > > I don't understand what went wrong after v8, but anyway, this one should
> > > > not be applied for now, since it's broken
> > > > 
> > > > 
> > > > Thank you
> > > > 
> > > > 
> > > 
> > > 
> > > Just to be clear: previous 15 patches _are_ tested and do not cause any
> > > misbehavior or bugs.
> > > 
> > > I guess, the stack buffer maybe the problem here, since it's the only
> > > change on this side since v8. I didn't have a chance to take a closer
> > > look, but I will do it on weekends, I hope :)
> > > 
> >
> > Oh, I found the problem by just looking at the code with clear mind:
> >
> > > -free_dvobj:
> > > -	if (status != _SUCCESS && pdvobjpriv) {
> > > +	if (pdvobjpriv) {
> > >  		usb_set_intfdata(usb_intf, NULL);
> > >  		kfree(pdvobjpriv);
> > >  		pdvobjpriv = NULL;
> >
> > This if should be deleted completely, because we don't want to fail on every
> > probe :)
> >
> > Sorry for noise... :(
> >
> > Greg, can you take first 15 patches, if they look good and then I will send
> > fixed version of 16? AFAIU, you are ok with taking part of the series
>
> Please fix up and resend the whole series as our tools work best by
> taking the whole thing.
>
> That way I "know" you tested them all :)

It is true, but there was small error on testing side from me this time.

I am testing with qemu and I forgot to copy new driver to qemu's shared 
folder (it was busy day or I was already asleep, idk). It resulted to 
testing old version of the driver. Next day I've tested new changes on 
top of this series and found the problem :)

I am sorry for kind of lying, i've already fixed it locally, so it won't 
happen again



With regards,
Pavel Skripkin