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

[Thinh Nguyen <Thinh.Nguyen@synopsys.com>]

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

BR,
Thinh