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

[Pavel Skripkin]

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


Thank you


With regards,
Pavel Skripkin