USB: reorganize urb->status use in ehci-hcd
This patch (as974) reorganizes the way ehci-hcd sets urb->status. It
now keeps the information in a local variable until the last moment.
The patch also simplifies the handling of -EREMOTEIO, since the only
use of that code is to set the do_status flag.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index a8f5408..794d27e 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -139,63 +139,65 @@
/*-------------------------------------------------------------------------*/
-static void qtd_copy_status (
+static int qtd_copy_status (
struct ehci_hcd *ehci,
struct urb *urb,
size_t length,
u32 token
)
{
+ int status = -EINPROGRESS;
+
/* count IN/OUT bytes, not SETUP (even short packets) */
if (likely (QTD_PID (token) != 2))
urb->actual_length += length - QTD_LENGTH (token);
/* don't modify error codes */
if (unlikely(urb->unlinked))
- return;
+ return status;
/* force cleanup after short read; not always an error */
if (unlikely (IS_SHORT_READ (token)))
- urb->status = -EREMOTEIO;
+ status = -EREMOTEIO;
/* serious "can't proceed" faults reported by the hardware */
if (token & QTD_STS_HALT) {
if (token & QTD_STS_BABBLE) {
/* FIXME "must" disable babbling device's port too */
- urb->status = -EOVERFLOW;
+ status = -EOVERFLOW;
} else if (token & QTD_STS_MMF) {
/* fs/ls interrupt xfer missed the complete-split */
- urb->status = -EPROTO;
+ status = -EPROTO;
} else if (token & QTD_STS_DBE) {
- urb->status = (QTD_PID (token) == 1) /* IN ? */
+ status = (QTD_PID (token) == 1) /* IN ? */
? -ENOSR /* hc couldn't read data */
: -ECOMM; /* hc couldn't write data */
} else if (token & QTD_STS_XACT) {
/* timeout, bad crc, wrong PID, etc; retried */
if (QTD_CERR (token))
- urb->status = -EPIPE;
+ status = -EPIPE;
else {
ehci_dbg (ehci, "devpath %s ep%d%s 3strikes\n",
urb->dev->devpath,
usb_pipeendpoint (urb->pipe),
usb_pipein (urb->pipe) ? "in" : "out");
- urb->status = -EPROTO;
+ status = -EPROTO;
}
/* CERR nonzero + no errors + halt --> stall */
} else if (QTD_CERR (token))
- urb->status = -EPIPE;
+ status = -EPIPE;
else /* unknown */
- urb->status = -EPROTO;
+ status = -EPROTO;
ehci_vdbg (ehci,
"dev%d ep%d%s qtd token %08x --> status %d\n",
usb_pipedevice (urb->pipe),
usb_pipeendpoint (urb->pipe),
usb_pipein (urb->pipe) ? "in" : "out",
- token, urb->status);
+ token, status);
/* if async CSPLIT failed, try cleaning out the TT buffer */
- if (urb->status != -EPIPE
+ if (status != -EPIPE
&& urb->dev->tt && !usb_pipeint (urb->pipe)
&& ((token & QTD_STS_MMF) != 0
|| QTD_CERR(token) == 0)
@@ -212,10 +214,12 @@
usb_hub_tt_clear_buffer (urb->dev, urb->pipe);
}
}
+
+ return status;
}
static void
-ehci_urb_done (struct ehci_hcd *ehci, struct urb *urb)
+ehci_urb_done(struct ehci_hcd *ehci, struct urb *urb, int status)
__releases(ehci->lock)
__acquires(ehci->lock)
{
@@ -231,17 +235,13 @@
qh_put (qh);
}
- spin_lock (&urb->lock);
if (unlikely(urb->unlinked)) {
COUNT(ehci->stats.unlink);
} else {
- if (likely(urb->status == -EINPROGRESS ||
- (urb->status == -EREMOTEIO &&
- !(urb->transfer_flags & URB_SHORT_NOT_OK))))
- urb->status = 0;
+ if (likely(status == -EINPROGRESS))
+ status = 0;
COUNT(ehci->stats.complete);
}
- spin_unlock (&urb->lock);
#ifdef EHCI_URB_TRACE
ehci_dbg (ehci,
@@ -249,13 +249,14 @@
__FUNCTION__, urb->dev->devpath, urb,
usb_pipeendpoint (urb->pipe),
usb_pipein (urb->pipe) ? "in" : "out",
- urb->status,
+ status,
urb->actual_length, urb->transfer_buffer_length);
#endif
/* complete() can reenter this HCD */
usb_hcd_unlink_urb_from_ep(ehci_to_hcd(ehci), urb);
spin_unlock (&ehci->lock);
+ urb->status = status;
usb_hcd_giveback_urb (ehci_to_hcd(ehci), urb);
spin_lock (&ehci->lock);
}
@@ -276,6 +277,7 @@
{
struct ehci_qtd *last = NULL, *end = qh->dummy;
struct list_head *entry, *tmp;
+ int last_status = -EINPROGRESS;
int stopped;
unsigned count = 0;
int do_status = 0;
@@ -304,6 +306,7 @@
struct ehci_qtd *qtd;
struct urb *urb;
u32 token = 0;
+ int qtd_status;
qtd = list_entry (entry, struct ehci_qtd, qtd_list);
urb = qtd->urb;
@@ -311,11 +314,12 @@
/* clean up any state from previous QTD ...*/
if (last) {
if (likely (last->urb != urb)) {
- ehci_urb_done (ehci, last->urb);
+ ehci_urb_done(ehci, last->urb, last_status);
count++;
}
ehci_qtd_free (ehci, last);
last = NULL;
+ last_status = -EINPROGRESS;
}
/* ignore urbs submitted during completions we reported */
@@ -351,13 +355,13 @@
stopped = 1;
if (unlikely (!HC_IS_RUNNING (ehci_to_hcd(ehci)->state)))
- urb->status = -ESHUTDOWN;
+ last_status = -ESHUTDOWN;
/* ignore active urbs unless some previous qtd
* for the urb faulted (including short read) or
* its urb was canceled. we may patch qh or qtds.
*/
- if (likely(urb->status == -EINPROGRESS &&
+ if (likely(last_status == -EINPROGRESS &&
!urb->unlinked))
continue;
@@ -386,14 +390,14 @@
}
/* remove it from the queue */
- spin_lock (&urb->lock);
- qtd_copy_status (ehci, urb, qtd->length, token);
- if (unlikely(urb->status == -EREMOTEIO)) {
+ qtd_status = qtd_copy_status(ehci, urb, qtd->length, token);
+ if (unlikely(qtd_status == -EREMOTEIO)) {
do_status = (!urb->unlinked &&
usb_pipecontrol(urb->pipe));
- urb->status = 0;
+ qtd_status = 0;
}
- spin_unlock (&urb->lock);
+ if (likely(last_status == -EINPROGRESS))
+ last_status = qtd_status;
if (stopped && qtd->qtd_list.prev != &qh->qtd_list) {
last = list_entry (qtd->qtd_list.prev,
@@ -406,7 +410,7 @@
/* last urb's completion might still need calling */
if (likely (last != NULL)) {
- ehci_urb_done (ehci, last->urb);
+ ehci_urb_done(ehci, last->urb, last_status);
count++;
ehci_qtd_free (ehci, last);
}