linux-kernel - [PATCH 04/19] usb: host xhci: Add XHCI_NEEDS_LHC

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: <1416921115-10467-5-git-send-email-george.cherian@ti.com>
Date:	Tue, 25 Nov 2014 18:41:40 +0530
From:	George Cherian <george.cherian@...com>
To:	<linux-arm-kernel@...ts.infradead.org>,
	<linux-kernel@...r.kernel.org>,
	<linux-samsung-soc@...r.kernel.org>, <linux-omap@...r.kernel.org>,
	<linux-usb@...r.kernel.org>
CC:	<peter.chen@...escale.com>, <sojka@...ica.cz>,
	<mathias.nyman@...el.com>, <balbi@...com>,
	<gregkh@...uxfoundation.org>, <tony@...mide.com>,
	<bcousson@...libre.com>, <kgene.kim@...sung.com>,
	<ben-linux@...ff.org>, <linux@....linux.org.uk>,
	<galak@...eaurora.org>, <ijc+devicetree@...lion.org.uk>,
	<mark.rutland@....com>, <pawel.moll@....com>, <robh+dt@...nel.org>,
	George Cherian <george.cherian@...com>
Subject: [PATCH 04/19] usb: host xhci: Add XHCI_NEEDS_LHC_RESET quirk

This adds XHCI_NEEDS_LHC_RESET quirk, to make sure only Light Host Reset
is done during xhci_reset(). This is mainly useful when we switch roles
HOST to Device mode and viceversa.

The DWC3 IP shares internal RAM for both HOST and Device specific registers.
So while switching roles between HOST and Device modes, it's advbised to do
a LIGHT HC reset else the already configured global registers of the DWC3 IP
gets re-initialized.

Signed-off-by: George Cherian <george.cherian@...com>
---
 drivers/usb/host/xhci.c | 5 +++--
 drivers/usb/host/xhci.h | 1 +
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index d4196f8..5dabf9a 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -170,11 +170,12 @@ int xhci_reset(struct xhci_hcd *xhci)
 
 	xhci_dbg_trace(xhci, trace_xhci_dbg_init, "// Reset the HC");
 	command = readl(&xhci->op_regs->command);
-	command |= CMD_RESET;
+	command |= (xhci->quirks & XHCI_NEEDS_LHC_RESET) ? CMD_LRESET : CMD_RESET;
 	writel(command, &xhci->op_regs->command);
 
 	ret = xhci_handshake(xhci, &xhci->op_regs->command,
-			CMD_RESET, 0, 10 * 1000 * 1000);
+			(xhci->quirks & XHCI_NEEDS_LHC_RESET) ? CMD_LRESET : CMD_RESET,
+			0, 10 * 1000 * 1000);
 	if (ret)
 		return ret;
 
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 2248058..1b14b09 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1561,6 +1561,7 @@ struct xhci_hcd {
 /* For controllers with a broken beyond repair streams implementation */
 #define XHCI_BROKEN_STREAMS	(1 << 19)
 #define XHCI_DRD_SUPPORT	(1 << 20)
+#define XHCI_NEEDS_LHC_RESET	(1 << 21)
 	unsigned int		num_active_eps;
 	unsigned int		limit_active_eps;
 	/* There are two roothubs to keep track of bus suspend info for */
-- 
1.8.3.1

--
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/