[PATCH] usb: host: ehci-sched: add comment about find_tt() not returning error

From: Sudip Mukherjee
Date: Sun Oct 11 2020 - 16:52:59 EST


Add a comment explaining why find_tt() will not return error even though
find_tt() is checking for NULL and other errors.

Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
---
drivers/usb/host/ehci-sched.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c
index 6dfb242f9a4b..0f85aa9b2fb1 100644
--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -244,6 +244,12 @@ static void reserve_release_intr_bandwidth(struct ehci_hcd *ehci,

/* FS/LS bus bandwidth */
if (tt_usecs) {
+ /*
+ * find_tt() will not return any error here as we have
+ * already called find_tt() before calling this function
+ * and checked for any error return. The previous call
+ * would have created the data structure.
+ */
tt = find_tt(qh->ps.udev);
if (sign > 0)
list_add_tail(&qh->ps.ps_list, &tt->ps_list);
@@ -1337,6 +1343,12 @@ static void reserve_release_iso_bandwidth(struct ehci_hcd *ehci,
}
}

+ /*
+ * find_tt() will not return any error here as we have
+ * already called find_tt() before calling this function
+ * and checked for any error return. The previous call
+ * would have created the data structure.
+ */
tt = find_tt(stream->ps.udev);
if (sign > 0)
list_add_tail(&stream->ps.ps_list, &tt->ps_list);
--
2.11.0