[3/4] usb: host: xhci-plat: revert "usb: host: xhci-plat: enable clk in resume timing"

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, Mar 08, 2018 at 05:17:16PM +0200, Mathias Nyman wrote:
> From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> 
> 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@renesas.com>
> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>

This really should go to 4.15-stable, right?  I'll go add the tag if
needed, but want your confirmation first.

thanks,

greg k-h
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