This patch revamps some common code-paths which are shared between (re-)initialization and suspend/resume subroutines. It also adds some helpful comments about quirks and associated difficulties. It's quite big, but it should fix #25382: <https://bugzilla.kernel.org/show_bug.cgi?id=25382> And hopefully the code is robust enough to deal with all possible suspend/resume scenarios without requiring the user to do any sort of manual and possibly dangerous work. Signed-off-by: Christian Lamparter <chunkeey@xxxxxxxxxxxxxx> --- drivers/net/wireless/ath/carl9170/usb.c | 53 +++++++++++++++++++++--------- 1 files changed, 37 insertions(+), 16 deletions(-) diff --git a/drivers/net/wireless/ath/carl9170/usb.c b/drivers/net/wireless/ath/carl9170/usb.c index 2d947a3..537732e 100644 --- a/drivers/net/wireless/ath/carl9170/usb.c +++ b/drivers/net/wireless/ath/carl9170/usb.c @@ -834,7 +834,7 @@ static int carl9170_usb_load_firmware(struct ar9170 *ar) if (err) goto err_out; - /* firmware restarts cmd counter */ + /* now, start the command response counter */ ar->cmd_seq = -1; return 0; @@ -851,7 +851,12 @@ int carl9170_usb_restart(struct ar9170 *ar) if (ar->intf->condition != USB_INTERFACE_BOUND) return 0; - /* Disable command response sequence counter. */ + /* + * Disable the command response sequence counter check. + * We already know that the device/firmware is in a bad state. + * So, no extra points are awarded to anyone who reminds the + * driver about that. + */ ar->cmd_seq = -2; err = carl9170_reboot(ar); @@ -903,6 +908,15 @@ static int carl9170_usb_init_device(struct ar9170 *ar) { int err; + /* + * The carl9170 firmware let's the driver know when it's + * ready for action. But we have to be prepared to gracefully + * handle all spurious [flushed] messages after each (re-)boot. + * Thus the command response counter remains disabled until it + * can be safely synchronized. + */ + ar->cmd_seq = -2; + err = carl9170_usb_send_rx_irq_urb(ar); if (err) goto err_out; @@ -911,14 +925,21 @@ static int carl9170_usb_init_device(struct ar9170 *ar) if (err) goto err_unrx; + err = carl9170_usb_open(ar); + if (err) + goto err_unrx; + mutex_lock(&ar->mutex); err = carl9170_usb_load_firmware(ar); mutex_unlock(&ar->mutex); if (err) - goto err_unrx; + goto err_stop; return 0; +err_stop: + carl9170_usb_stop(ar); + err_unrx: carl9170_usb_cancel_urbs(ar); @@ -964,10 +985,6 @@ static void carl9170_usb_firmware_finish(struct ar9170 *ar) if (err) goto err_freefw; - err = carl9170_usb_open(ar); - if (err) - goto err_unrx; - err = carl9170_register(ar); carl9170_usb_stop(ar); @@ -1043,7 +1060,6 @@ static int carl9170_usb_probe(struct usb_interface *intf, atomic_set(&ar->rx_work_urbs, 0); atomic_set(&ar->rx_anch_urbs, 0); atomic_set(&ar->rx_pool_urbs, 0); - ar->cmd_seq = -2; usb_get_dev(ar->udev); @@ -1090,10 +1106,6 @@ static int carl9170_usb_suspend(struct usb_interface *intf, carl9170_usb_cancel_urbs(ar); - /* - * firmware automatically reboots for usb suspend. - */ - return 0; } @@ -1106,12 +1118,20 @@ static int carl9170_usb_resume(struct usb_interface *intf) return -ENODEV; usb_unpoison_anchored_urbs(&ar->rx_anch); + carl9170_set_state(ar, CARL9170_STOPPED); - err = carl9170_usb_init_device(ar); - if (err) - goto err_unrx; + /* + * The USB documentation demands that [for suspend] all traffic + * to and from the device has to stop. This would be fine, but + * there's a catch: the device[usb phy] does not come back. + * + * Upon resume the firmware will "kill" itself and the + * boot-code sorts out the magic voodoo. + * Not very nice, but there's not much what could go wrong. + */ + msleep(1100); - err = carl9170_usb_open(ar); + err = carl9170_usb_init_device(ar); if (err) goto err_unrx; @@ -1133,6 +1153,7 @@ static struct usb_driver carl9170_driver = { #ifdef CONFIG_PM .suspend = carl9170_usb_suspend, .resume = carl9170_usb_resume, + .reset_resume = carl9170_usb_resume, #endif /* CONFIG_PM */ }; -- 1.7.2.3 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
