linux-kernel - [PATCH v4 6/9] usb: dwc3: save/restore OTG registers during suspend/resume

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]

Date:	Wed, 2 Sep 2015 17:24:21 +0300
From:	Roger Quadros <rogerq@...com>
To:	<balbi@...com>
CC:	<tony@...mide.com>, <Joao.Pinto@...opsys.com>,
	<sergei.shtylyov@...entembedded.com>, <peter.chen@...escale.com>,
	<jun.li@...escale.com>, <linux-usb@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>, <linux-omap@...r.kernel.org>,
	Roger Quadros <rogerq@...com>
Subject: [PATCH v4 6/9] usb: dwc3: save/restore OTG registers during suspend/resume

Without this we loose OTG controller register context and malfunction
after a system suspend-resume.

Signed-off-by: Roger Quadros <rogerq@...com>
---
 drivers/usb/dwc3/core.c | 17 +++++++++++++++++
 drivers/usb/dwc3/core.h |  6 +++++-
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 632ee53..684010c 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -56,6 +56,7 @@ void dwc3_set_mode(struct dwc3 *dwc, u32 mode)
 	reg = dwc3_readl(dwc->regs, DWC3_GCTL);
 	reg &= ~(DWC3_GCTL_PRTCAPDIR(DWC3_GCTL_PRTCAP_OTG));
 	reg |= DWC3_GCTL_PRTCAPDIR(mode);
+	dwc->current_mode = mode;
 	dwc3_writel(dwc->regs, DWC3_GCTL, reg);
 }
 
@@ -1443,6 +1444,14 @@ static int dwc3_suspend(struct device *dev)
 
 	spin_lock_irqsave(&dwc->lock, flags);
 
+	/* Save OTG state only if we're really using it */
+	if (dwc->current_mode == DWC3_GCTL_PRTCAP_OTG) {
+		dwc->ocfg = dwc3_readl(dwc->regs, DWC3_OCFG);
+		dwc->octl = dwc3_readl(dwc->regs, DWC3_OCTL);
+		dwc->oevt = dwc3_readl(dwc->regs, DWC3_OEVT);
+		dwc->oevten = dwc3_readl(dwc->regs, DWC3_OEVTEN);
+	}
+
 	switch (dwc->dr_mode) {
 	case USB_DR_MODE_PERIPHERAL:
 	case USB_DR_MODE_OTG:
@@ -1486,6 +1495,14 @@ static int dwc3_resume(struct device *dev)
 	dwc3_event_buffers_setup(dwc);
 	dwc3_writel(dwc->regs, DWC3_GCTL, dwc->gctl);
 
+	/* Restore OTG state only if we're really using it */
+	if (dwc->current_mode == DWC3_GCTL_PRTCAP_OTG) {
+		dwc3_writel(dwc->regs, DWC3_OCFG, dwc->ocfg);
+		dwc3_writel(dwc->regs, DWC3_OCTL, dwc->octl);
+		dwc3_writel(dwc->regs, DWC3_OEVT, dwc->oevt);
+		dwc3_writel(dwc->regs, DWC3_OEVTEN, dwc->oevten);
+	}
+
 	switch (dwc->dr_mode) {
 	case USB_DR_MODE_PERIPHERAL:
 	case USB_DR_MODE_OTG:
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 129ef37..1115ce0 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -737,6 +737,7 @@ struct dwc3_scratchpad_array {
  * @regs: base address for our registers
  * @regs_size: address space size
  * @oevten: otg interrupt enable mask copy
+ * @current_mode: current mode of operation written to PRTCAPDIR
  * @nr_scratch: number of scratch buffers
  * @num_event_buffers: calculated number of event buffers
  * @u1u2: only used on revisions <1.83a for workaround
@@ -858,9 +859,12 @@ struct dwc3 {
 	/* used for suspend/resume */
 	u32			dcfg;
 	u32			gctl;
-
+	u32			ocfg;
+	u32			octl;
+	u32			oevt;
 	u32			oevten;
 
+	u32			current_mode;
 	u32			nr_scratch;
 	u32			num_event_buffers;
 	u32			u1u2;
-- 
2.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/