Re: [PATCH 1/1] Staging: hv: Move the mouse driver out of staging

[Greg KH <gregkh@suse.de>]

On Wed, Nov 09, 2011 at 12:45:30AM +0000, KY Srinivasan wrote:
> 
> 
> > -----Original Message-----
> > From: Dmitry Torokhov [mailto:dmitry.torokhov@gmail.com]
> > Sent: Monday, November 07, 2011 12:51 AM
> > To: KY Srinivasan
> > Cc: gregkh@suse.de; linux-kernel@vger.kernel.org;
> > devel@linuxdriverproject.org; virtualization@lists.osdl.org; ohering@suse.com;
> > joe@perches.com; jkosina@suse.cz
> > Subject: Re: [PATCH 1/1] Staging: hv: Move the mouse driver out of staging
> > 
> > Hi K. Y,
> > 
> > On Mon, Nov 07, 2011 at 01:04:53AM +0000, KY Srinivasan wrote:
> > >
> > >
> > > > -----Original Message-----
> > > > From: Dmitry Torokhov [mailto:dmitry.torokhov@gmail.com]
> > > > Sent: Saturday, November 05, 2011 2:48 AM
> > > > To: KY Srinivasan
> > > > Cc: gregkh@suse.de; linux-kernel@vger.kernel.org;
> > > > devel@linuxdriverproject.org; virtualization@lists.osdl.org;
> > ohering@suse.com;
> > > > joe@perches.com; jkosina@suse.cz
> > > > Subject: Re: [PATCH 1/1] Staging: hv: Move the mouse driver out of staging
> > > >
> > > > Hi KY,
> > >
> > > Dimitry,
> > >
> > > Let me begin by thanking you for taking the time to review. I have incorporated
> > > pretty much all your suggestions.
> > 
> > Thank you very much for considering my suggestions.
> 
> > 
> > > >
> > > > Instead of potentially ever-increasing buffer that you also allocate
> > > > (and it looks like leaking on every callback invocation) can you just
> > > > repeat the read if you know that there are more data and use single
> > > > pre-allocated buffer?
> > >
> > > The ring-buffer protocol is such that we need to consume the full message.
> > > Also, why do you say we are leaking memory?
> > 
> > Ah, OK, I see, we keep reading until read returns 0-sized reply and then
> > we free the buffer... Never mind then.
> > 
> > > > > +
> > > > > +	hid_dev->ll_driver = &mousevsc_ll_driver;
> > > > > +	hid_dev->driver = &mousevsc_hid_driver;
> > > >
> > > > You are not really hid driver; you are more of a "provider" so why do
> > > > you need to set hid_dev->driver in addition to hid_dev->ll_driver?
> > > >
> > > True, but hid_parse_report() expects that the driver field be set; so I
> > > need to fake this.
> > 
> > If you supply .parse() method for your mousevsc_ll_driver structure and
> > call hid_parse_report() from it then HID core will set the default
> > driver and call parse at appropriate time.
> 
> Would it be ok if I were to make this change after Jiri accepts the driver out of staging?

Why not fix this now?  No need to take a driver that is known to have
issues, right?

greg k-h