Hi,
On 08/09/2017 03:58 PM, Mathias Nyman wrote:
> On 27.07.2017 05:21, Lu Baolu wrote:
>> xhci_disable_slot() is a helper for disabling a slot when a device
>> goes away or recovers from error situations. Currently, it checks
>> the corespoding virt-dev pointer and returns directly (w/o issuing
>> disable slot command) if it's null.
>>
>> This is unnecessary and will cause problems in case where virt-dev
>> allocation fails and xhci_disable_slot() is called to roll back the
>> hardware state. Refer to the implementation of xhci_alloc_dev().
>>
>
> True, checking for xhci->devs[slot_id] doesn't work if xhci_alloc_dev()
> failed xhci_alloc_virt_device() and calls xhci_disable_slot,
>
> but the virt dev check is needed for test mode, which will just try
> to disable all slots from 1 to HCS_MAX_SLOTS:
>
> xhci_enter_test_mode(..)
> /* Disable all Device Slots */
> for (i = 1; i <= HCS_MAX_SLOTS(xhci->hcs_params1); i++) {
> retval = xhci_disable_slot(xhci, NULL, i);
>
>
So, how about checking virt dev before this invoking?
@@ -612,10 +612,12 @@ static int xhci_enter_test_mode(struct xhci_hcd *xhci,
xhci_dbg(xhci, "Disable all slots\n");
spin_unlock_irqrestore(&xhci->lock, *flags);
for (i = 1; i <= HCS_MAX_SLOTS(xhci->hcs_params1); i++) {
- retval = xhci_disable_slot(xhci, NULL, i);
- if (retval)
- xhci_err(xhci, "Failed to disable slot %d, %d. Enter test mode anyway\n",
- i, retval);
+ if (xhci->devs[i]) {
+ retval = xhci_disable_slot(xhci, NULL, i);
+ if (retval)
+ xhci_err(xhci, "Failed to disable slot %d, %d. Enter test mode anyway\n",
+ i, retval);
+ }
}
spin_lock_irqsave(&xhci->lock, *flags);
/* Put all ports to the Disable state by clear PP */
Best regards,
Lu Baolu
>
>> This patch removes lines to check virt-dev in xhci_disable_slot().
>>
>> Fixes: f9e609b82479 ("usb: xhci: Add helper function xhci_disable_slot().")
>> Cc: Guoqing Zhang <guoqing.zhang@xxxxxxxxx>
>> Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
>> ---
>> drivers/usb/host/xhci.c | 4 ----
>> 1 file changed, 4 deletions(-)
>>
>> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
>> index b2ff1ff..e69073f 100644
>> --- a/drivers/usb/host/xhci.c
>> +++ b/drivers/usb/host/xhci.c
>> @@ -3567,11 +3567,7 @@ int xhci_disable_slot(struct xhci_hcd *xhci, struct xhci_command *command,
>> unsigned long flags;
>> u32 state;
>> int ret = 0;
>> - struct xhci_virt_device *virt_dev;
>>
>> - virt_dev = xhci->devs[slot_id];
>> - if (!virt_dev)
>> - return -EINVAL;
>> if (!command)
>> command = xhci_alloc_command(xhci, false, false, GFP_KERNEL);
>> if (!command)
>>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
