diff mbox series

[v2,2/3] usb: xhci-mtk: fix a short packet issue of gen1 isoc-in transfer

Message ID 20231215073431.8512-2-chunfeng.yun@mediatek.com (mailing list archive)
State Superseded
Headers show
Series [v2,1/3] dt-bindings: usb: mtk-xhci: add a property for Gen1 isoc-in transfer issue | expand

Commit Message

Chunfeng Yun (云春峰) Dec. 15, 2023, 7:34 a.m. UTC
For Gen1 isoc-in transfer, host still send out unexpected ACK after device
finish the burst with a short packet, this will cause an exception on the
connected device, such as, a usb 4k camera.
It can be fixed by setting rxfifo depth less than 3, prefer to use 2 here,
the side-effect is that may cause performance drop about 10%, including
bulk transfer.

Fixes: 926d60ae64a6 ("usb: xhci-mtk: modify the SOF/ITP interval for mt8195")
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v2:
use 'rx-fifo-depth' property;
add header file 'linux/bitfield.h' to avoid building error on some ARCH;
---
 drivers/usb/host/xhci-mtk.c | 38 +++++++++++++++++++++++++++++++++++--
 drivers/usb/host/xhci-mtk.h |  2 ++
 2 files changed, 38 insertions(+), 2 deletions(-)

Comments

Greg KH Dec. 15, 2023, 12:39 p.m. UTC | #1
On Fri, Dec 15, 2023 at 03:34:30PM +0800, Chunfeng Yun wrote:
> For Gen1 isoc-in transfer, host still send out unexpected ACK after device
> finish the burst with a short packet, this will cause an exception on the
> connected device, such as, a usb 4k camera.
> It can be fixed by setting rxfifo depth less than 3, prefer to use 2 here,
> the side-effect is that may cause performance drop about 10%, including
> bulk transfer.
> 
> Fixes: 926d60ae64a6 ("usb: xhci-mtk: modify the SOF/ITP interval for mt8195")
> Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> ---
> v2:
> use 'rx-fifo-depth' property;
> add header file 'linux/bitfield.h' to avoid building error on some ARCH;
> ---


Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
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If you wish to discuss this problem further, or you have questions about
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thanks,

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diff mbox series

Patch

diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
index bbdf1b0b7be1..dad6c9873d79 100644
--- a/drivers/usb/host/xhci-mtk.c
+++ b/drivers/usb/host/xhci-mtk.c
@@ -7,6 +7,7 @@ 
  *  Chunfeng Yun <chunfeng.yun@mediatek.com>
  */
 
+#include <linux/bitfield.h>
 #include <linux/dma-mapping.h>
 #include <linux/iopoll.h>
 #include <linux/kernel.h>
@@ -73,6 +74,9 @@ 
 #define FRMCNT_LEV1_RANG	(0x12b << 8)
 #define FRMCNT_LEV1_RANG_MASK	GENMASK(19, 8)
 
+#define HSCH_CFG1		0x960
+#define SCH3_RXFIFO_DEPTH_MASK	GENMASK(21, 20)
+
 #define SS_GEN2_EOF_CFG		0x990
 #define SSG2EOF_OFFSET		0x3c
 
@@ -165,6 +169,34 @@  static void xhci_mtk_set_frame_interval(struct xhci_hcd_mtk *mtk)
 	writel(value, hcd->regs + SS_GEN2_EOF_CFG);
 }
 
+/*
+ * workaround: usb3.2 gen1 isoc rx hw issue
+ * host send out unexpected ACK afer device fininsh a burst transfer with
+ * a short packet.
+ */
+static void xhci_mtk_rxfifo_depth_set(struct xhci_hcd_mtk *mtk)
+{
+	struct usb_hcd *hcd = mtk->hcd;
+	u32 value;
+
+	if (mtk->rxfifo_depth < 0)
+		return;
+
+	value = readl(hcd->regs + HSCH_CFG1);
+	value &= ~SCH3_RXFIFO_DEPTH_MASK;
+	value |= FIELD_PREP(SCH3_RXFIFO_DEPTH_MASK, mtk->rxfifo_depth);
+	writel(value, hcd->regs + HSCH_CFG1);
+}
+
+static void xhci_mtk_init_quirk(struct xhci_hcd_mtk *mtk)
+{
+	/* workaround only for mt8195 */
+	xhci_mtk_set_frame_interval(mtk);
+
+	/* workaround for SoCs using SSUSB about before IPM v1.6.0 */
+	xhci_mtk_rxfifo_depth_set(mtk);
+}
+
 static int xhci_mtk_host_enable(struct xhci_hcd_mtk *mtk)
 {
 	struct mu3c_ippc_regs __iomem *ippc = mtk->ippc_regs;
@@ -448,8 +480,7 @@  static int xhci_mtk_setup(struct usb_hcd *hcd)
 		if (ret)
 			return ret;
 
-		/* workaround only for mt8195 */
-		xhci_mtk_set_frame_interval(mtk);
+		xhci_mtk_init_quirk(mtk);
 	}
 
 	ret = xhci_gen_setup(hcd, xhci_mtk_quirks);
@@ -527,6 +558,9 @@  static int xhci_mtk_probe(struct platform_device *pdev)
 	of_property_read_u32(node, "mediatek,u2p-dis-msk",
 			     &mtk->u2p_dis_msk);
 
+	mtk->rxfifo_depth = -1;
+	of_property_read_u32(node, "rx-fifo-depth", &mtk->rxfifo_depth);
+
 	ret = usb_wakeup_of_property_parse(mtk, node);
 	if (ret) {
 		dev_err(dev, "failed to parse uwk property\n");
diff --git a/drivers/usb/host/xhci-mtk.h b/drivers/usb/host/xhci-mtk.h
index 39f7ae7d3087..2d27bb0d3ecb 100644
--- a/drivers/usb/host/xhci-mtk.h
+++ b/drivers/usb/host/xhci-mtk.h
@@ -171,6 +171,8 @@  struct xhci_hcd_mtk {
 	struct regmap *uwk;
 	u32 uwk_reg_base;
 	u32 uwk_vers;
+
+	int rxfifo_depth;
 };
 
 static inline struct xhci_hcd_mtk *hcd_to_mtk(struct usb_hcd *hcd)