Re: [PATCH v7] usb: dwc3: core: Workaround for CSR read timeout

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Jun 21, 2024 at 05:42:42AM +0000, Thinh Nguyen wrote:
> On Fri, Jun 21, 2024, Greg KH wrote:
> > On Fri, Jun 21, 2024 at 09:40:10AM +0800, joswang wrote:
> > > On Fri, Jun 21, 2024 at 1:16 AM Greg KH <gregkh@linuxfoundation.org> wrote:
> > > >
> > > > On Wed, Jun 19, 2024 at 07:45:29PM +0800, joswang wrote:
> > > > > From: Jos Wang <joswang@lenovo.com>
> > > > >
> > > > > This is a workaround for STAR 4846132, which only affects
> > > > > DWC_usb31 version2.00a operating in host mode.
> > > > >
> > > > > There is a problem in DWC_usb31 version 2.00a operating
> > > > > in host mode that would cause a CSR read timeout When CSR
> > > > > read coincides with RAM Clock Gating Entry. By disable
> > > > > Clock Gating, sacrificing power consumption for normal
> > > > > operation.
> > > > >
> > > > > Cc: stable@vger.kernel.org
> > > > > Signed-off-by: Jos Wang <joswang@lenovo.com>
> > > >
> > > > What commit id does this fix?  How far back should it be backported in
> > > > the stable releases?
> > > >
> > > > thanks,
> > > >
> > > > greg k-h
> > > 
> > > Hello Greg Thinh
> > > 
> > > It seems first begin from the commit 1e43c86d84fb ("usb: dwc3: core:
> > > Add DWC31 version 2.00a controller")
> > > in 6.8.0-rc6 branch ?
> > 
> > That commit showed up in 6.9, not 6.8.  And if so, please resend with a
> > proper "Fixes:" tag.
> > 
> 
> This patch workarounds the controller's issue.

So it fixes a bug?  Or does not fix a bug?  I'm confused.

> It doesn't resolve any
> particular commit that requires a "Fixes" tag. So, this should go on
> "next". It can be backported as needed.

Who would do the backporting and when?

> If it's to be backported, it can
> probably go back to as far as v4.3, to commit 690fb3718a70 ("usb: dwc3:
> Support Synopsys USB 3.1 IP"). But you'd need to collect all the
> dependencies including the commit mention above.

I don't understand, sorry.  Is this just a normal "evolve the driver to
work better" change, or is it a "fix broken code" change, or is it
something else?

In other words, what do you want to see happen to this?  What tree(s)
would you want it applied to?

thanks,

greg k-h