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@vger.kernel.org Signed-off-by: Chunfeng Yun chunfeng.yun@mediatek.com --- 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@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) + 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)