[PATCH 13/17] usb: xhci-mtk: add some schedule error number

Chunfeng Yun
2021-03-05T09:04:07Z

This is used to provide more information about which case
causes bandwidth schedule failure.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
drivers/usb/host/xhci-mtk-sch.c | 44 ++++++++++++++++++++++++++-------
1 file changed, 35 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/host/xhci-mtk-sch.c b/drivers/usb/host/xhci-mtk-sch.c
index d39545ade9a1..deb918490b71 100644
--- a/drivers/usb/host/xhci-mtk-sch.c
+++ b/drivers/usb/host/xhci-mtk-sch.c
@@ -25,6 +25,13 @@
*/
#define TT_MICROFRAMES_MAX 9

+/* schedule error type */
+#define ESCH_SS_Y6 1001
+#define ESCH_SS_OVERLAP 1002
+#define ESCH_CS_OVERFLOW 1003
+#define ESCH_BW_OVERFLOW 1004
+#define ESCH_FIXME 1005
+
/* mtk scheduler bitmasks */
#define EP_BPKTS(p) ((p) & 0x7f)
#define EP_BCSCOUNT(p) (((p) & 0x7) << 8)
@@ -32,6 +39,24 @@
#define EP_BOFFSET(p) ((p) & 0x3fff)
#define EP_BREPEAT(p) (((p) & 0x7fff) << 16)

+static char *sch_error_string(int err_num)
+{
+ switch (err_num) {
+ case ESCH_SS_Y6:
+ return "Can't schedule Start-Split in Y6";
+ case ESCH_SS_OVERLAP:
+ return "Can't find a suitable Start-Split location";
+ case ESCH_CS_OVERFLOW:
+ return "The last Complete-Split is greater than 7";
+ case ESCH_BW_OVERFLOW:
+ return "Bandwidth exceeds the maximum limit";
+ case ESCH_FIXME:
+ return "FIXME, to be resolved";
+ default:
+ return "Unknown";
+ }
+}
+
static int is_fs_or_ls(enum usb_device_speed speed)
{
return speed == USB_SPEED_FULL || speed == USB_SPEED_LOW;
@@ -412,7 +437,7 @@ static int check_fs_bus_bw(struct mu3h_sch_ep_info *sch_ep, int offset)
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 -ESCH_BW_OVERFLOW;
}
}

@@ -437,11 +462,11 @@ static int check_sch_tt(struct mu3h_sch_ep_info *sch_ep, u32 offset)
* must never schedule Start-Split in Y6
*/
if (!(start_ss == 7 || last_ss < 6))
- return -ERANGE;
+ return -ESCH_SS_Y6;

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

} else {
u32 cs_count = DIV_ROUND_UP(sch_ep->maxpkt, FS_PAYLOAD_MAX);
@@ -451,14 +476,14 @@ static int check_sch_tt(struct mu3h_sch_ep_info *sch_ep, u32 offset)
* must never schedule Start-Split in Y6
*/
if (start_ss == 6)
- return -ERANGE;
+ return -ESCH_SS_Y6;

/* one uframe for ss + one uframe for idle */
start_cs = (start_ss + 2) % 8;
last_cs = start_cs + cs_count - 1;

if (last_cs > 7)
- return -ERANGE;
+ return -ESCH_CS_OVERFLOW;

if (sch_ep->ep_type == ISOC_IN_EP)
extra_cs_count = (last_cs == 7) ? 1 : 2;
@@ -470,7 +495,7 @@ static int check_sch_tt(struct mu3h_sch_ep_info *sch_ep, u32 offset)
cs_count = 7; /* HW limit */

if (test_bit(offset, tt->ss_bit_map))
- return -ERANGE;
+ return -ESCH_SS_OVERLAP;

sch_ep->cs_count = cs_count;
/* one for ss, the other for idle */
@@ -562,7 +587,7 @@ static int check_sch_bw(struct mu3h_sch_bw_info *sch_bw,
u32 esit_boundary;
u32 min_num_budget;
u32 min_cs_count;
- int ret;
+ int ret = 0;

/*
* Search through all possible schedule microframes.
@@ -597,7 +622,7 @@ static int check_sch_bw(struct mu3h_sch_bw_info *sch_bw,
bw_boundary = get_bw_boundary(sch_ep->speed);
/* check bandwidth */
if (min_bw > bw_boundary)
- return -ERANGE;
+ return ret ? ret : -ESCH_BW_OVERFLOW;

sch_ep->offset = min_index;
sch_ep->cs_count = min_cs_count;
@@ -765,7 +790,8 @@ int xhci_mtk_check_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)

ret = check_sch_bw(sch_bw, sch_ep);
if (ret) {
- xhci_err(xhci, "Not enough bandwidth!\n");
+ xhci_err(xhci, "Not enough bandwidth! (%s)\n",
+ sch_error_string(-ret));
return -ENOSPC;
}
}
--
2.18.0