Greg:
This patch changes the return codes used by hub_port_wait_reset(),
hub_port_reset(), and hub_port_debounce() in hub.c. I couldn't stand the
{-1=error, 0=okay, 1=disconnect} scheme; the meanings seemed arbitrary and
I constantly forgot which number stood for what status. The revised code
uses normal negative error codes, including -ENOTCONN to indicate device
disconnected, or 0 for success.
Please apply.
Alan Stern
P.S.: When hub_port_wait_reset() detects that the port isn't connected, it
returns an indication that the device has gone away. But when it detects
a connection status change, it simply returns an error. It seems to me
that a connect change should be just as definitive as a not-connected
status; either way it means the device was unplugged from the port. If
there was a connect change and something is connected now, then we should
go back to the debounce step instead of continuing to try resetting the
port. Agreed?
P.P.S.: The hub_port_debounce() function doesn't behave as one would
expect from the comments at the top. I trust no one will object if I
rewrite it to make the routine do what it's supposed to do?
# This is a BitKeeper generated patch for the following project:
# Project Name: greg k-h's linux 2.5 USB kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
# ChangeSet 1.2113 -> 1.2114
# drivers/usb/core/hub.c 1.157 -> 1.158
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 04/05/25 [EMAIL PROTECTED] 1.2114
# Use normal return codes for several routines in hub.c
# --------------------------------------------
#
diff -Nru a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
--- a/drivers/usb/core/hub.c Tue May 25 16:25:41 2004
+++ b/drivers/usb/core/hub.c Tue May 25 16:25:41 2004
@@ -859,7 +859,6 @@
#define HUB_LONG_RESET_TIME 200
#define HUB_RESET_TIMEOUT 500
-/* return: -1 on error, 0 on success, 1 on disconnect. */
static int hub_port_wait_reset(struct usb_device *hdev, int port,
struct usb_device *udev, unsigned int delay)
{
@@ -875,17 +874,16 @@
/* read and decode port status */
ret = hub_port_status(hdev, port, &portstatus, &portchange);
- if (ret < 0) {
- return -1;
- }
+ if (ret < 0)
+ return ret;
/* Device went away? */
if (!(portstatus & USB_PORT_STAT_CONNECTION))
- return 1;
+ return -ENOTCONN;
/* bomb out completely if something weird happened */
if ((portchange & USB_PORT_STAT_C_CONNECTION))
- return -1;
+ return -EINVAL;
/* if we`ve finished resetting, then break out of the loop */
if (!(portstatus & USB_PORT_STAT_RESET) &&
@@ -908,10 +906,9 @@
port + 1, delay);
}
- return -1;
+ return -EBUSY;
}
-/* return: -1 on error, 0 on success, 1 on disconnect. */
static int hub_port_reset(struct usb_device *hdev, int port,
struct usb_device *udev, unsigned int delay)
{
@@ -924,7 +921,7 @@
/* return on disconnect or reset */
status = hub_port_wait_reset(hdev, port, udev, delay);
- if (status != -1) {
+ if (status == -ENOTCONN || status == 0) {
clear_port_feature(hdev,
port + 1, USB_PORT_FEAT_C_RESET);
udev->state = status
@@ -943,7 +940,7 @@
"Cannot enable port %i. Maybe the USB cable is bad?\n",
port + 1);
- return -1;
+ return status;
}
static int hub_port_disable(struct usb_device *hdev, int port)
@@ -976,7 +973,6 @@
#define HUB_DEBOUNCE_STEP 25
#define HUB_DEBOUNCE_STABLE 4
-/* return: -1 on error, 0 on success, 1 on disconnect. */
static int hub_port_debounce(struct usb_device *hdev, int port)
{
int ret;
@@ -991,7 +987,7 @@
ret = hub_port_status(hdev, port, &portstatus, &portchange);
if (ret < 0)
- return -1;
+ return ret;
if ((portstatus & USB_PORT_STAT_CONNECTION) == connection) {
if (connection) {
@@ -1012,7 +1008,7 @@
"debounce: port %d: delay %dms stable %d status 0x%x\n",
port + 1, delay_time, stable_count, portstatus);
- return ((portstatus&USB_PORT_STAT_CONNECTION)) ? 0 : 1;
+ return (portstatus & USB_PORT_STAT_CONNECTION) ? 0 : -ENOTCONN;
}
static int hub_set_address(struct usb_device *udev)
@@ -1045,7 +1041,7 @@
{
static DECLARE_MUTEX(usb_address0_sem);
- int i, j, retval = -ENODEV;
+ int i, j, retval;
unsigned delay = HUB_SHORT_RESET_TIME;
enum usb_device_speed oldspeed = udev->speed;
@@ -1063,15 +1059,12 @@
down(&usb_address0_sem);
/* Reset the device; full speed may morph to high speed */
- switch (hub_port_reset(hdev, port, udev, delay)) {
- case 0: /* success, speed is known */
- break;
- case 1: /* disconnect, give to companion */
- retval = -EBUSY;
- /* FALL THROUGH */
- default: /* error */
+ retval = hub_port_reset(hdev, port, udev, delay);
+ if (retval < 0) /* error or disconnect */
goto fail;
- }
+ /* success, speed is known */
+ retval = -ENODEV;
+
if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) {
dev_dbg(&udev->dev, "device reset changed speed!\n");
goto fail;
@@ -1329,7 +1322,7 @@
/* reset, set address, get descriptor, add to hub's children */
down (&udev->serialize);
status = hub_port_init(hdev, udev, port);
- if (status == -EBUSY)
+ if (status == -ENOTCONN)
break;
if (status < 0)
continue;
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