[PATCH 02/17] usb: xhci-mtk: improve bandwidth scheduling with TT

Chunfeng Yun
2021-03-05T09:04:05Z

When the USB headset is plug into an external hub, sometimes
can't set config due to not enough bandwidth, so need improve
LS/FS INT/ISOC bandwidth scheduling with TT.

Fixes: 54f6a8af3722 ("usb: xhci-mtk: skip dropping bandwidth of unchecked endpoints")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Yaqii Wu <yaqii.wu@mediatek.com>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
drivers/usb/host/xhci-mtk-sch.c | 74 ++++++++++++++++++++++++++-------
drivers/usb/host/xhci-mtk.h | 6 ++-
2 files changed, 64 insertions(+), 16 deletions(-)

diff --git a/drivers/usb/host/xhci-mtk-sch.c b/drivers/usb/host/xhci-mtk-sch.c
index 5891f56c64da..8950d1f10a7f 100644
--- a/drivers/usb/host/xhci-mtk-sch.c
+++ b/drivers/usb/host/xhci-mtk-sch.c
@@ -378,6 +378,31 @@ static void update_bus_bw(struct mu3h_sch_bw_info *sch_bw,
sch_ep->allocated = used;
}

+static int check_fs_bus_bw(struct mu3h_sch_ep_info *sch_ep, int offset)
+{
+ struct mu3h_sch_tt *tt = sch_ep->sch_tt;
+ u32 num_esit, tmp;
+ int base;
+ int i, j;
+
+ num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
+ for (i = 0; i < num_esit; i++) {
+ base = offset + i * sch_ep->esit;
+
+ /*
+ * Compared with hs bus, no matter what ep type,
+ * the hub will always delay one uframe to send data
+ */
+ for (j = 0; j < sch_ep->cs_count; j++) {
+ tmp = tt->fs_bus_bw[base + j] + sch_ep->bw_cost_per_microframe;
+ if (tmp > FS_PAYLOAD_MAX)
+ return -ERANGE;
+ }
+ }
+
+ return 0;
+}
+
static int check_sch_tt(struct usb_device *udev,
struct mu3h_sch_ep_info *sch_ep, u32 offset)
{
@@ -402,7 +427,7 @@ static int check_sch_tt(struct usb_device *udev,
return -ERANGE;

for (i = 0; i < sch_ep->cs_count; i++)
- if (test_bit(offset + i, tt->split_bit_map))
+ if (test_bit(offset + i, tt->ss_bit_map))
return -ERANGE;

} else {
@@ -432,7 +457,7 @@ static int check_sch_tt(struct usb_device *udev,
cs_count = 7; /* HW limit */

for (i = 0; i < cs_count + 2; i++) {
- if (test_bit(offset + i, tt->split_bit_map))
+ if (test_bit(offset + i, tt->ss_bit_map))
return -ERANGE;
}

@@ -448,24 +473,44 @@ static int check_sch_tt(struct usb_device *udev,
sch_ep->num_budget_microframes = sch_ep->esit;
}

- return 0;
+ return check_fs_bus_bw(sch_ep, offset);
}

static void update_sch_tt(struct usb_device *udev,
- struct mu3h_sch_ep_info *sch_ep)
+ struct mu3h_sch_ep_info *sch_ep, bool used)
{
struct mu3h_sch_tt *tt = sch_ep->sch_tt;
u32 base, num_esit;
+ int bw_updated;
+ int bits;
int i, j;

num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
+ bits = (sch_ep->ep_type == ISOC_OUT_EP) ? sch_ep->cs_count : 1;
+
+ if (used)
+ bw_updated = sch_ep->bw_cost_per_microframe;
+ else
+ bw_updated = -sch_ep->bw_cost_per_microframe;
+
for (i = 0; i < num_esit; i++) {
base = sch_ep->offset + i * sch_ep->esit;
- for (j = 0; j < sch_ep->num_budget_microframes; j++)
- set_bit(base + j, tt->split_bit_map);
+
+ for (j = 0; j < bits; j++) {
+ if (used)
+ set_bit(base + j, tt->ss_bit_map);
+ else
+ clear_bit(base + j, tt->ss_bit_map);
+ }
+
+ for (j = 0; j < sch_ep->cs_count; j++)
+ tt->fs_bus_bw[base + j] += bw_updated;
}

- list_add_tail(&sch_ep->tt_endpoint, &tt->ep_list);
+ if (used)
+ list_add_tail(&sch_ep->tt_endpoint, &tt->ep_list);
+ else
+ list_del(&sch_ep->tt_endpoint);
}

static int check_sch_bw(struct usb_device *udev,
@@ -535,7 +580,7 @@ static int check_sch_bw(struct usb_device *udev,
if (!tt_offset_ok)
return -ERANGE;

- update_sch_tt(udev, sch_ep);
+ update_sch_tt(udev, sch_ep, 1);
}

/* update bus bandwidth info */
@@ -548,15 +593,16 @@ static void destroy_sch_ep(struct usb_device *udev,
struct mu3h_sch_bw_info *sch_bw, struct mu3h_sch_ep_info *sch_ep)
{
/* only release ep bw check passed by check_sch_bw() */
- if (sch_ep->allocated)
+ if (sch_ep->allocated) {
update_bus_bw(sch_bw, sch_ep, 0);
+ if (sch_ep->sch_tt)
+ update_sch_tt(udev, sch_ep, 0);
+ }

- list_del(&sch_ep->endpoint);
-
- if (sch_ep->sch_tt) {
- list_del(&sch_ep->tt_endpoint);
+ if (sch_ep->sch_tt)
drop_tt(udev);
- }
+
+ list_del(&sch_ep->endpoint);
kfree(sch_ep);
}

diff --git a/drivers/usb/host/xhci-mtk.h b/drivers/usb/host/xhci-mtk.h
index cbb09dfea62e..f42769c69249 100644
--- a/drivers/usb/host/xhci-mtk.h
+++ b/drivers/usb/host/xhci-mtk.h
@@ -20,13 +20,15 @@
#define XHCI_MTK_MAX_ESIT 64

/**
- * @split_bit_map: used to avoid split microframes overlay
+ * @ss_bit_map: used to avoid start split microframes overlay
+ * @fs_bus_bw: array to keep track of bandwidth already used for FS
* @ep_list: Endpoints using this TT
* @usb_tt: usb TT related
* @tt_port: TT port number
*/
struct mu3h_sch_tt {
- DECLARE_BITMAP(split_bit_map, XHCI_MTK_MAX_ESIT);
+ DECLARE_BITMAP(ss_bit_map, XHCI_MTK_MAX_ESIT);
+ u32 fs_bus_bw[XHCI_MTK_MAX_ESIT];
struct list_head ep_list;
struct usb_tt *usb_tt;
int tt_port;
--
2.18.0