On Tue, 4 Dec 2012, Sarah Sharp wrote:
> A USB 3.0 device can transition to the Inactive state if a U1 or U2 exit
> transition fails. The current code in hub_events simply issues a warm
> reset, but does not call any pre-reset or post-reset driver methods (or
> unbind/rebind drivers without them). Therefore the drivers won't know
> their device has just been reset.
>
> hub_events should instead call usb_reset_device. This means
> hub_port_reset now needs to figure out whether it should issue a warm
> reset or a hot reset.
>
> Remove the FIXME note about needing disconnect() for a NOTATTACHED
> device. This patch fixes that.
Actually, I think it was fixed many years ago but the FIXME comment
was never removed. :-)
> Signed-off-by: Sarah Sharp <sarah.a.sh...@linux.intel.com>
> ---
> drivers/usb/core/hub.c | 29 ++++++++++++++++++++++++-----
> 1 files changed, 24 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index a502857..9341302 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -2609,7 +2609,6 @@ static void hub_port_finish_reset(struct usb_hub *hub,
> int port1,
> case -ENODEV:
> clear_port_feature(hub->hdev,
> port1, USB_PORT_FEAT_C_RESET);
> - /* FIXME need disconnect() for NOTATTACHED device */
> if (hub_is_superspeed(hub->hdev)) {
> clear_port_feature(hub->hdev, port1,
> USB_PORT_FEAT_C_BH_PORT_RESET);
> @@ -2643,6 +2642,18 @@ static int hub_port_reset(struct usb_hub *hub, int
> port1,
> * Some companion controllers don't like it when they mix.
> */
> down_read(&ehci_cf_port_reset_rwsem);
> + } else if (!warm) {
> + /*
> + * If the caller hasn't explicitly requested a warm reset,
> + * double check and see if one is needed.
> + */
> + status = hub_port_status(hub, port1,
> + &portstatus, &portchange);
> + if (status < 0)
> + goto done;
> +
> + if (hub_port_warm_reset_required(hub, portstatus))
> + warm = true;
Would it be better to turn "warm" into a 3-valued argument: true,
false, or dont_know? Then this test could be skipped if the caller
wanted to do a regular reset.
Alan Stern
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