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From:   Prashanth K <quic_prashk@quicinc.com>
To:     <stable@vger.kernel.org>, Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
        "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>
CC:     Mathias Nyman <mathias.nyman@intel.com>,
        Tejas Joglekar <joglekar@synopsys.com>,
        <linux-kernel@vger.kernel.org>, <linux-usbyy@vger.kernel.org>,
        Prashanth K <quic_prashk@quicinc.com>
Subject: [PATCH 1/2] usb: dwc3: core: Add support for xhci-sg-trb-cache-size-quirk
Date:   Sat, 18 Nov 2023 11:24:54 +0530
Message-ID: <20231118055455.249088-2-quic_prashk@quicinc.com>
In-Reply-To: <20231118055455.249088-1-quic_prashk@quicinc.com>
References: <20231118055455.249088-1-quic_prashk@quicinc.com>
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Upstream commit bac1ec551434 ("usb: xhci: Set quirk for
XHCI_SG_TRB_CACHE_SIZE_QUIRK") introduced a new quirk in XHCI
which fixes XHC timeout while using SG buffers. Add a new quirk
in DWC3 layer to enable this XHCI quirk since this is needed
for DWC3 controller. Added xhci private data structure to pass
the quirk to XHCI.

In Synopsys DWC3 databook,
Table 9-3: xHCI Debug Capability Limitations
Chained TRBs greater than TRB cache size: The debug capability
driver must not create a multi-TRB TD that describes smaller
than a 1K packet that spreads across 8 or more TRBs on either
the IN TR or the OUT TR

Cc: <stable@vger.kernel.org> # 5.11
Fixes: bac1ec551434 ("usb: xhci: Set quirk for XHCI_SG_TRB_CACHE_SIZE_QUIRK")
Signed-off-by: Prashanth K <quic_prashk@quicinc.com>
---
 drivers/usb/dwc3/core.c | 2 ++
 drivers/usb/dwc3/core.h | 3 +++
 drivers/usb/dwc3/host.c | 9 +++++++++
 3 files changed, 14 insertions(+)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 0328c86..c6b0ae9 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1633,6 +1633,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
 				"snps,parkmode-disable-hs-quirk");
 	dwc->gfladj_refclk_lpm_sel = device_property_read_bool(dev,
 				"snps,gfladj-refclk-lpm-sel-quirk");
+	dwc->xhci_sg_trb_cache_size_quirk = device_property_read_bool(dev,
+				"xhci-sg-trb-cache-size-quirk");
 
 	dwc->tx_de_emphasis_quirk = device_property_read_bool(dev,
 				"snps,tx_de_emphasis_quirk");
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index efe6caf..dde1447 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1119,6 +1119,8 @@ struct dwc3_scratchpad_array {
  *			instances in park mode.
  * @gfladj_refclk_lpm_sel: set if we need to enable SOF/ITP counter
  *                          running based on ref_clk
+ * @xhci_sg_trb_cache_size_quirk: set to prevent XHC timeout when scatter-gather
+ *			is enabled due to TRB_CACHE_SIZE.
  * @tx_de_emphasis_quirk: set if we enable Tx de-emphasis quirk
  * @tx_de_emphasis: Tx de-emphasis value
  *	0	- -6dB de-emphasis
@@ -1342,6 +1344,7 @@ struct dwc3 {
 	unsigned		parkmode_disable_ss_quirk:1;
 	unsigned		parkmode_disable_hs_quirk:1;
 	unsigned		gfladj_refclk_lpm_sel:1;
+	unsigned		xhci_sg_trb_cache_size_quirk:1;
 
 	unsigned		tx_de_emphasis_quirk:1;
 	unsigned		tx_de_emphasis:2;
diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
index 61f57fe..09f049b 100644
--- a/drivers/usb/dwc3/host.c
+++ b/drivers/usb/dwc3/host.c
@@ -63,6 +63,7 @@ int dwc3_host_init(struct dwc3 *dwc)
 {
 	struct property_entry	props[4];
 	struct platform_device	*xhci;
+	struct xhci_plat_priv   dwc3_xhci_plat_priv = {0};
 	int			ret, irq;
 	int			prop_idx = 0;
 
@@ -87,6 +88,14 @@ int dwc3_host_init(struct dwc3 *dwc)
 		goto err;
 	}
 
+	if (dwc->xhci_sg_trb_cache_size_quirk)
+		dwc3_xhci_plat_priv.quirks |= XHCI_SG_TRB_CACHE_SIZE_QUIRK;
+
+	ret = platform_device_add_data(xhci, &dwc3_xhci_plat_priv,
+					sizeof(dwc3_xhci_plat_priv));
+	if (ret)
+		goto err;
+
 	memset(props, 0, sizeof(struct property_entry) * ARRAY_SIZE(props));
 
 	if (dwc->usb3_lpm_capable)
-- 
2.7.4