linux-kernel - [PATCH AUTOSEL 6.0 07/67] usb: host: xhci-plat: suspend and resume clocks

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20221013001554.1892206-7-sashal@kernel.org>
Date:   Wed, 12 Oct 2022 20:14:48 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Justin Chen <justinpopo6@...il.com>,
        Florian Fainelli <f.fainelli@...il.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Sasha Levin <sashal@...nel.org>, mathias.nyman@...el.com,
        linux-usb@...r.kernel.org
Subject: [PATCH AUTOSEL 6.0 07/67] usb: host: xhci-plat: suspend and resume clocks

From: Justin Chen <justinpopo6@...il.com>

[ Upstream commit 8bd954c56197caf5e3a804d989094bc3fe6329aa ]

Introduce XHCI_SUSPEND_RESUME_CLKS quirk as a means to suspend and resume
clocks if the hardware is capable of doing so. We assume that clocks will
be needed if the device may wake.

Reviewed-by: Florian Fainelli <f.fainelli@...il.com>
Signed-off-by: Justin Chen <justinpopo6@...il.com>
Link: https://lore.kernel.org/r/1660170455-15781-2-git-send-email-justinpopo6@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/usb/host/xhci-plat.c | 16 +++++++++++++++-
 drivers/usb/host/xhci.h      |  1 +
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index a8641b6536ee..ef10982ad482 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -437,7 +437,16 @@ static int __maybe_unused xhci_plat_suspend(struct device *dev)
 	 * xhci_suspend() needs `do_wakeup` to know whether host is allowed
 	 * to do wakeup during suspend.
 	 */
-	return xhci_suspend(xhci, device_may_wakeup(dev));
+	ret = xhci_suspend(xhci, device_may_wakeup(dev));
+	if (ret)
+		return ret;
+
+	if (!device_may_wakeup(dev) && (xhci->quirks & XHCI_SUSPEND_RESUME_CLKS)) {
+		clk_disable_unprepare(xhci->clk);
+		clk_disable_unprepare(xhci->reg_clk);
+	}
+
+	return 0;
 }
 
 static int __maybe_unused xhci_plat_resume(struct device *dev)
@@ -446,6 +455,11 @@ static int __maybe_unused xhci_plat_resume(struct device *dev)
 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
 	int ret;
 
+	if (!device_may_wakeup(dev) && (xhci->quirks & XHCI_SUSPEND_RESUME_CLKS)) {
+		clk_prepare_enable(xhci->clk);
+		clk_prepare_enable(xhci->reg_clk);
+	}
+
 	ret = xhci_priv_resume_quirk(hcd);
 	if (ret)
 		return ret;
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 7caa0db5e826..6dfbf73ee840 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1899,6 +1899,7 @@ struct xhci_hcd {
 #define XHCI_NO_SOFT_RETRY	BIT_ULL(40)
 #define XHCI_BROKEN_D3COLD	BIT_ULL(41)
 #define XHCI_EP_CTX_BROKEN_DCS	BIT_ULL(42)
+#define XHCI_SUSPEND_RESUME_CLKS	BIT_ULL(43)
 
 	unsigned int		num_active_eps;
 	unsigned int		limit_active_eps;
-- 
2.35.1