USB: EHCI: convert singly-linked lists to list_heads
This patch (as1664) converts ehci-hcd's async_unlink, async_iaa, and
intr_unlink from singly-linked lists to standard doubly-linked
list_heads. Originally it didn't seem necessary to use list_heads,
because items are always added to and removed from these lists in FIFO
order. But now with more list processing going on, it's easier to use
the standard routines than continue with a roll-your-own approach.
I don't know if the code ends up being notably shorter, but the
patterns will be more familiar to any kernel hacker.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 6815209..13f6704 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -128,9 +128,8 @@
/* async schedule support */
struct ehci_qh *async;
struct ehci_qh *dummy; /* For AMD quirk use */
- struct ehci_qh *async_unlink;
- struct ehci_qh *async_unlink_last;
- struct ehci_qh *async_iaa;
+ struct list_head async_unlink;
+ struct list_head async_iaa;
unsigned async_unlink_cycle;
unsigned async_count; /* async activity count */
@@ -143,8 +142,7 @@
unsigned i_thresh; /* uframes HC might cache */
union ehci_shadow *pshadow; /* mirror hw periodic table */
- struct ehci_qh *intr_unlink;
- struct ehci_qh *intr_unlink_last;
+ struct list_head intr_unlink;
unsigned intr_unlink_cycle;
unsigned now_frame; /* frame from HC hardware */
unsigned last_iso_frame; /* last frame scanned for iso */
@@ -380,7 +378,7 @@
struct list_head qtd_list; /* sw qtd list */
struct list_head intr_node; /* list of intr QHs */
struct ehci_qtd *dummy;
- struct ehci_qh *unlink_next; /* next on unlink list */
+ struct list_head unlink_node;
unsigned unlink_cycle;