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Date:   Fri, 27 Mar 2020 14:05:18 +0530
Message-Id: <e3458b468d280a8d0cc6f3b49c63016e7b60586e.1585297723.git.joglekar@synopsys.com>
In-Reply-To: <cover.1585297723.git.joglekar@synopsys.com>
References: <cover.1585297723.git.joglekar@synopsys.com>
From:   Tejas Joglekar <Tejas.Joglekar@synopsys.com>
Subject: [RFC PATCH 2/4] usb: xhci: Set quirk for XHCI_CONSOLIDATE_SG_LIST
To:     Tejas Joglekar <Tejas.Joglekar@synopsys.com>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        Mathias Nyman <mathias.nyman@intel.com>
Cc:     John Youn <John.Youn@synopsys.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

This commit enables the quirk when the consolidate_trbs property is set
for the Synopsys xHC. This patch fixes the SNPS xHC hang issue
when the data is scattered across small buffers which does not make
atleast MPS size for given TRB cache size of SNPS xHC.

Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
---
 drivers/usb/host/xhci-pci.c  | 3 +++
 drivers/usb/host/xhci-plat.c | 3 +++
 drivers/usb/host/xhci.h      | 1 +
 3 files changed, 7 insertions(+)

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 766b74723e64..cdda8e2de1c2 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -268,6 +268,9 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
 	     pdev->device == 0x9026)
 		xhci->quirks |= XHCI_RESET_PLL_ON_DISCONNECT;
 
+	if (pdev->vendor == PCI_VENDOR_ID_SYNOPSYS)
+		xhci->quirks |= XHCI_CONSOLIDATE_SG_LIST;
+
 	if (xhci->quirks & XHCI_RESET_ON_RESUME)
 		xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
 				"QUIRK: Resetting on resume");
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 315b4552693c..8333c78dcf03 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -289,6 +289,9 @@ static int xhci_plat_probe(struct platform_device *pdev)
 		if (device_property_read_bool(tmpdev, "quirk-broken-port-ped"))
 			xhci->quirks |= XHCI_BROKEN_PORT_PED;
 
+		if (device_property_read_bool(tmpdev, "consolidate-sgl"))
+			xhci->quirks |= XHCI_CONSOLIDATE_SG_LIST;
+
 		device_property_read_u32(tmpdev, "imod-interval-ns",
 					 &xhci->imod_interval);
 	}
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 3289bb516201..a093eeaec70e 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1873,6 +1873,7 @@ struct xhci_hcd {
 #define XHCI_DEFAULT_PM_RUNTIME_ALLOW	BIT_ULL(33)
 #define XHCI_RESET_PLL_ON_DISCONNECT	BIT_ULL(34)
 #define XHCI_SNPS_BROKEN_SUSPEND    BIT_ULL(35)
+#define XHCI_CONSOLIDATE_SG_LIST    BIT_ULL(36)
 
 	unsigned int		num_active_eps;
 	unsigned int		limit_active_eps;
-- 
2.11.0