On Fri, Jun 21, 2024, Greg KH wrote: > 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@xxxxxxxxxxxxxxxxxxx> wrote: > > > > > > > > > > On Wed, Jun 19, 2024 at 07:45:29PM +0800, joswang wrote: > > > > > > From: Jos Wang <joswang@xxxxxxxxxx> > > > > > > > > > > > > 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@xxxxxxxxxxxxxxx > > > > > > Signed-off-by: Jos Wang <joswang@xxxxxxxxxx> > > > > > > > > > > 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. The bug is not a driver's bug. The fix applies to a hardware bug and not any particular commit that can be referenced with a "Fixes" tag. > > > 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? For anyone who doesn't use mainline kernel that needs this patch backported to their kernel version. > > > 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? > It's up to you, but it seems to fit "usb-testing" branch more since it doesn't have a "Fixes" tag. The severity of this fix is debatable since it doesn't apply to every DWC_usb31 configuration or every scenario. Thanks, Thinh