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 4k bytes, prefer to use
3k 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")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
---
v3:
add Cc stable
change @rxfifo_depth from int to u32, due to property's value range is changed
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 | 37 +++++++++++++++++++++++++++++++++++--
drivers/usb/host/xhci-mtk.h | 2 ++
2 files changed, 37 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
index bbdf1b0b7be1..868793b82348 100644
--- a/drivers/usb/host/xhci-mtk.c
+++ b/drivers/usb/host/xhci-mtk.c
@@ -7,6 +7,7 @@
* Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
*/
+#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)
+ return;
+
+ value = readl(hcd->regs + HSCH_CFG1);
+ value &= ~SCH3_RXFIFO_DEPTH_MASK;
+ value |= FIELD_PREP(SCH3_RXFIFO_DEPTH_MASK, mtk->rxfifo_depth - 1);
+ 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 +558,8 @@ static int xhci_mtk_probe(struct platform_device *pdev)
of_property_read_u32(node, "mediatek,u2p-dis-msk",
&mtk->u2p_dis_msk);
+ 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..f5e2bd66bb1b 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;
+ /* quirk */
+ u32 rxfifo_depth;
};
static inline struct xhci_hcd_mtk *hcd_to_mtk(struct usb_hcd *hcd)
--
2.18.0
