On Fri, Mar 09, 2018 at 01:48:37AM +0000, Yoshihiro Shimoda wrote:
> Hi Greg,
>
> > From: Greg KH, Sent: Friday, March 9, 2018 2:06 AM
> >
> > On Thu, Mar 08, 2018 at 05:17:16PM +0200, Mathias Nyman wrote:
> > > From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
> > >
> > > This patch reverts the commit 835e4241e714 ("usb: host: xhci-plat:
> > > enable clk in resume timing") because this driver also has runtime PM
> > > and the commit 560869100b99 ("clk: renesas: cpg-mssr: Restore module
> > > clocks during resume") will restore the clock on R-Car H3 environment.
> > >
> > > If the xhci_plat_suspend() disables the clk, the system cannot enable
> > > the clk in resume like the following behavior:
> > >
> > > < In resume >
> > > - genpd_resume_noirq() runs and enable the clk (enable_count = 1)
> > > - cpg_mssr_resume_noirq() restores the clk register.
> > > -- Since the clk was disabled in suspend, cpg_mssr_resume_noirq()
> > > will disable the clk and keep the enable_count.
> > > - Even if xhci_plat_resume() calls clk_prepare_enable(), since
> > > the enable_count is 1, the clk will be not enabled.
> > >
> > > After this patch is applied, the cpg-mssr driver will save the clk
> > > as enable, so the clk will be enabled in resume.
> > >
> > > Fixes: 835e4241e714 ("usb: host: xhci-plat: enable clk in resume timing")
> > > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
> > > Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
> >
> > This really should go to 4.15-stable, right? I'll go add the tag if
> > needed, but want your confirmation first.
>
> Since 4.15 is not longterm release, I think Renesas will not consume 4.15.
But it fixes a bug in 4.15, so someone might care :)
> So, I don't think this really should go to 4.15-stable.
> In such case, should I not add Fixes: tag? If not, I'll be careful in the future.
No, the fixes tag was great. I'll just leave it as-is.
thanks,
greg k-h
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