[PATCH] usb: xhci-mtk: fix in-ep's start-split check failure

From: Chunfeng Yun
Date: Fri Nov 17 2023 - 22:30:34 EST


It's wrong to use the data length in a CS (in uframe x) to check whether
there is a SS (in uframe x-2), because for a isoc-in ep, it may need some
CS to receive data;
Save the count of SS in a uframe for isoc/intr in-eps to fix the issue.

Fixes: 5c954e030f55 ("usb: xhci-mtk: improve split scheduling by separate IN/OUT budget")
Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
---
drivers/usb/host/xhci-mtk-sch.c | 13 ++++++++++---
drivers/usb/host/xhci-mtk.h | 2 ++
2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci-mtk-sch.c b/drivers/usb/host/xhci-mtk-sch.c
index 5b3cd455adec..61f3f8bbdcea 100644
--- a/drivers/usb/host/xhci-mtk-sch.c
+++ b/drivers/usb/host/xhci-mtk-sch.c
@@ -650,9 +650,8 @@ static int check_isoc_ss_overlap(struct mu3h_sch_ep_info *sch_ep, u32 offset)

if (sch_ep->ep_type == ISOC_OUT_EP) {
for (j = 0; j < sch_ep->num_budget_microframes; j++) {
- k = XHCI_MTK_BW_INDEX(base + j + CS_OFFSET);
- /* use cs to indicate existence of in-ss @(base+j) */
- if (tt->fs_bus_bw_in[k])
+ k = XHCI_MTK_BW_INDEX(base + j);
+ if (tt->in_ss_cnt[k])
return -ESCH_SS_OVERLAP;
}
} else if (sch_ep->ep_type == ISOC_IN_EP || sch_ep->ep_type == INT_IN_EP) {
@@ -769,6 +768,14 @@ static void update_sch_tt(struct mu3h_sch_ep_info *sch_ep, bool used)
tt->fs_frame_bw[f] -= (u16)sch_ep->bw_budget_table[j];
}
}
+
+ if (sch_ep->ep_type == ISOC_IN_EP || sch_ep->ep_type == INT_IN_EP) {
+ k = XHCI_MTK_BW_INDEX(base);
+ if (used)
+ tt->in_ss_cnt[k]++;
+ else
+ tt->in_ss_cnt[k]--;
+ }
}

if (used)
diff --git a/drivers/usb/host/xhci-mtk.h b/drivers/usb/host/xhci-mtk.h
index 865b55e23b15..39f7ae7d3087 100644
--- a/drivers/usb/host/xhci-mtk.h
+++ b/drivers/usb/host/xhci-mtk.h
@@ -38,6 +38,7 @@
* @fs_bus_bw_in: save bandwidth used by FS/LS IN eps in each uframes
* @ls_bus_bw: save bandwidth used by LS eps in each uframes
* @fs_frame_bw: save bandwidth used by FS/LS eps in each FS frames
+ * @in_ss_cnt: the count of Start-Split for IN eps
* @ep_list: Endpoints using this TT
*/
struct mu3h_sch_tt {
@@ -45,6 +46,7 @@ struct mu3h_sch_tt {
u16 fs_bus_bw_in[XHCI_MTK_MAX_ESIT];
u8 ls_bus_bw[XHCI_MTK_MAX_ESIT];
u16 fs_frame_bw[XHCI_MTK_FRAMES_CNT];
+ u8 in_ss_cnt[XHCI_MTK_MAX_ESIT];
struct list_head ep_list;
};

--
2.25.1