4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Yoshihiro Shimoda yoshihiro.shimoda.uh@renesas.com
[ Upstream commit d56e57ca030c8b4296944a2ae61ac167bf979c07 ]
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 Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/host/xhci-plat.c | 11 +---------- 1 file changed, 1 insertion(+), 10 deletions(-)
--- a/drivers/usb/host/xhci-plat.c +++ b/drivers/usb/host/xhci-plat.c @@ -355,7 +355,6 @@ static int __maybe_unused xhci_plat_susp { struct usb_hcd *hcd = dev_get_drvdata(dev); struct xhci_hcd *xhci = hcd_to_xhci(hcd); - int ret;
/* * xhci_suspend() needs `do_wakeup` to know whether host is allowed @@ -365,12 +364,7 @@ static int __maybe_unused xhci_plat_susp * reconsider this when xhci_plat_suspend enlarges its scope, e.g., * also applies to runtime suspend. */ - ret = xhci_suspend(xhci, device_may_wakeup(dev)); - - if (!device_may_wakeup(dev) && !IS_ERR(xhci->clk)) - clk_disable_unprepare(xhci->clk); - - return ret; + return xhci_suspend(xhci, device_may_wakeup(dev)); }
static int __maybe_unused xhci_plat_resume(struct device *dev) @@ -379,9 +373,6 @@ static int __maybe_unused xhci_plat_resu struct xhci_hcd *xhci = hcd_to_xhci(hcd); int ret;
- if (!device_may_wakeup(dev) && !IS_ERR(xhci->clk)) - clk_prepare_enable(xhci->clk); - ret = xhci_priv_resume_quirk(hcd); if (ret) return ret;