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From:   Pavankumar Kondeti <quic_pkondeti@quicinc.com>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Mathias Nyman <mathias.nyman@intel.com>
CC:     <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <quic_ugoswami@quicinc.com>, Jung Daehwan <dh10.jung@samsung.com>,
        Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Subject: [PATCH v2] xhci: reduce xhci_handshake timeout in xhci_reset
Date:   Mon, 14 Feb 2022 17:50:16 +0530
Message-ID: <1644841216-1468-1-git-send-email-quic_pkondeti@quicinc.com>
In-Reply-To: <1644836663-29220-1-git-send-email-quic_pkondeti@quicinc.com>
References: <1644836663-29220-1-git-send-email-quic_pkondeti@quicinc.com>
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From: Daehwan Jung <dh10.jung@samsung.com>

xhci_reset() is called with interrupts disabled. Waiting 10 seconds for
controller reset and controller ready operations can be fatal to the
system when controller is timed out. Reduce the timeout to 1 second
and print a error message when the time out happens.

Fixes: 22ceac191211 ("xhci: Increase reset timeout for Renesas 720201 host.")
Signed-off-by: Daehwan Jung <dh10.jung@samsung.com>
Signed-off-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
---

v2:
- Add error print statements in the code that change log refers to

 drivers/usb/host/xhci.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index dc357ca..bb9ea3f 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -196,9 +196,11 @@ int xhci_reset(struct xhci_hcd *xhci)
 		udelay(1000);
 
 	ret = xhci_handshake(&xhci->op_regs->command,
-			CMD_RESET, 0, 10 * 1000 * 1000);
-	if (ret)
+			CMD_RESET, 0, 1 * 1000 * 1000);
+	if (ret) {
+		xhci_err(xhci, "Host controller reset timed out\n");
 		return ret;
+	}
 
 	if (xhci->quirks & XHCI_ASMEDIA_MODIFY_FLOWCONTROL)
 		usb_asmedia_modifyflowcontrol(to_pci_dev(xhci_to_hcd(xhci)->self.controller));
@@ -210,7 +212,11 @@ int xhci_reset(struct xhci_hcd *xhci)
 	 * than status until the "Controller Not Ready" flag is cleared.
 	 */
 	ret = xhci_handshake(&xhci->op_regs->status,
-			STS_CNR, 0, 10 * 1000 * 1000);
+			STS_CNR, 0, 1 * 1000 * 1000);
+	if (ret) {
+		xhci_err(xhci, "Host controller is not ready within timeout\n");
+		return ret;
+	}
 
 	xhci->usb2_rhub.bus_state.port_c_suspend = 0;
 	xhci->usb2_rhub.bus_state.suspended_ports = 0;
-- 
2.7.4