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From: Wesley Cheng <quic_wcheng@quicinc.com>
To: <mathias.nyman@intel.com>, <gregkh@linuxfoundation.org>
Cc: <linux-kernel@vger.kernel.org>, <linux-usb@vger.kernel.org>,
	Wesley Cheng <quic_wcheng@quicinc.com>
Subject: [PATCH v3 1/2] usb: host: xhci: Do not re-initialize the XHCI HC if being removed
Date: Wed, 31 May 2023 15:27:18 -0700	[thread overview]
Message-ID: <20230531222719.14143-2-quic_wcheng@quicinc.com> (raw)
In-Reply-To: <20230531222719.14143-1-quic_wcheng@quicinc.com>

During XHCI resume, if there was a host controller error detected the
routine will attempt to re-initialize the XHCI HC, so that it can return
back to an operational state.  If the XHCI host controller is being
removed, this sequence would be already handled within the XHCI halt path,
leading to a duplicate set of reg ops/calls.  In addition, since the XHCI
bus is being removed, the overhead added in restarting the HCD is
unnecessary.  Check for the XHC state before setting the reinit_xhc
parameter, which is responsible for triggering the restart.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 drivers/usb/host/xhci.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index b81313ffeb76..02a30b883bde 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1028,7 +1028,8 @@ int xhci_resume(struct xhci_hcd *xhci, pm_message_t msg)
 	temp = readl(&xhci->op_regs->status);
 
 	/* re-initialize the HC on Restore Error, or Host Controller Error */
-	if (temp & (STS_SRE | STS_HCE)) {
+	if ((temp & (STS_SRE | STS_HCE)) &&
+	    !(xhci->xhc_state & XHCI_STATE_REMOVING)) {
 		reinit_xhc = true;
 		if (!xhci->broken_suspend)
 			xhci_warn(xhci, "xHC error in resume, USBSTS 0x%x, Reinit\n", temp);

  reply	other threads:[~2023-05-31 22:27 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-31 22:27 [PATCH v3 0/2] Avoid re-initializing XHCI HC during removal Wesley Cheng
2023-05-31 22:27 ` Wesley Cheng [this message]
2023-05-31 22:27 ` [PATCH v3 2/2] usb: host: xhci-plat: Set XHCI_STATE_REMOVING before resuming XHCI HC Wesley Cheng
2023-06-21 19:46 ` [PATCH v3 0/2] Avoid re-initializing XHCI HC during removal Wesley Cheng
2023-06-26 12:36   ` Mathias Nyman

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