After the loop `for (i = 0; i < config->desc.bNumInterfaces; i++)' if no
break occurred, i equals config->desc.bNumInterfaces. so if
usb_control_msg() failed then after goto reset_old_alts we read from
config->interface[config->desc.bNumInterfaces].
Signed-off-by: Roel Kluin <[email protected]>
---
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 9bc95fe..00b49bc 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1466,10 +1466,15 @@ int usb_reset_configuration(struct usb_device *dev)
retval = usb_hcd_alloc_bandwidth(dev, NULL,
intf->cur_altsetting, alt);
if (retval < 0)
- break;
+ /* If not, reinstate the old alternate settings */
+ goto reset_old_alts;
}
- /* If not, reinstate the old alternate settings */
+ retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
+ USB_REQ_SET_CONFIGURATION, 0,
+ config->desc.bConfigurationValue, 0,
+ NULL, 0, USB_CTRL_SET_TIMEOUT);
if (retval < 0) {
+ i--;
reset_old_alts:
for (; i >= 0; i--) {
struct usb_interface *intf = config->interface[i];
@@ -1485,12 +1490,6 @@ reset_old_alts:
mutex_unlock(&hcd->bandwidth_mutex);
return retval;
}
- retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
- USB_REQ_SET_CONFIGURATION, 0,
- config->desc.bConfigurationValue, 0,
- NULL, 0, USB_CTRL_SET_TIMEOUT);
- if (retval < 0)
- goto reset_old_alts;
mutex_unlock(&hcd->bandwidth_mutex);
/* re-init hc/hcd interface/endpoint state */
On Tue, Feb 09, 2010 at 02:00:05PM +0100, Roel Kluin wrote:
> After the loop `for (i = 0; i < config->desc.bNumInterfaces; i++)' if no
> break occurred, i equals config->desc.bNumInterfaces. so if
> usb_control_msg() failed then after goto reset_old_alts we read from
> config->interface[config->desc.bNumInterfaces].
>
> Signed-off-by: Roel Kluin <[email protected]>
Have you seen this happen on real hardware?
curious,
greg k-h
On Tue, Feb 9, 2010 at 2:08 PM, Greg KH <[email protected]> wrote:
> On Tue, Feb 09, 2010 at 02:00:05PM +0100, Roel Kluin wrote:
>> After the loop `for (i = 0; i < config->desc.bNumInterfaces; i++)' if no
>> break occurred, i equals config->desc.bNumInterfaces. so if
>> usb_control_msg() failed then after goto reset_old_alts we read from
>> config->interface[config->desc.bNumInterfaces].
>>
>> Signed-off-by: Roel Kluin <[email protected]>
>
> Have you seen this happen on real hardware?
>
> curious,
>
> greg k-h
>
No, I just found it in the code,
Thanks, Roel
On Tue, 9 Feb 2010, Roel Kluin wrote:
> After the loop `for (i = 0; i < config->desc.bNumInterfaces; i++)' if no
> break occurred, i equals config->desc.bNumInterfaces. so if
> usb_control_msg() failed then after goto reset_old_alts we read from
> config->interface[config->desc.bNumInterfaces].
You correctly identified a problem, but your fix is wrong -- or at
least, it is much too complicated. The proper fix goes like this:
/* If not, reinstate the old alternate settings */
if (retval < 0) {
reset_old_alts:
- for (; i >= 0; i--) {
+ for (i--; i >= 0; i--) {
struct usb_interface *intf = config->interface[i];
struct usb_host_interface *alt;
Alan Stern
After the loop `for (i = 0; i < config->desc.bNumInterfaces; i++)' if no
break occurred, i equals config->desc.bNumInterfaces. so if
usb_control_msg() failed then after goto reset_old_alts we read from
config->interface[config->desc.bNumInterfaces].
We can safely decrement i as well if the break occurred.
Signed-off-by: Roel Kluin <[email protected]>
Acked-by: Alan Stern <[email protected]>
---
> You correctly identified a problem, but your fix is wrong -- or at
> least, it is much too complicated.
Ok,
drivers/usb/core/message.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 9bc95fe..1a48aac 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1471,7 +1471,7 @@ int usb_reset_configuration(struct usb_device *dev)
/* If not, reinstate the old alternate settings */
if (retval < 0) {
reset_old_alts:
- for (; i >= 0; i--) {
+ for (i--; i >= 0; i--) {
struct usb_interface *intf = config->interface[i];
struct usb_host_interface *alt;
After the loop `for (i = 0; i < config->desc.bNumInterfaces; i++)' if no
break occurred, i equals config->desc.bNumInterfaces. so if
usb_control_msg() failed then after goto reset_old_alts we read from
config->interface[config->desc.bNumInterfaces].
Reported-by: "Juha Leppanen" <[email protected]>
Signed-off-by: Roel Kluin <[email protected]>
---
>> You correctly identified a problem, but your fix is wrong -- or at
>> least, it is much too complicated. The proper fix goes like this:
>
> /* If not, reinstate the old alternate settings */
> if (retval < 0) {
> reset_old_alts:
> - for (; i >= 0; i--) {
> + for (i--; i >= 0; i--) {
> struct usb_interface *intf = config->interface[i];
> struct usb_host_interface *alt;
Are you really sure this is better? If usb_hcd_alloc_bandwidth() fails,
in the loop _before_ the reset_old_alts label, don't we still have to
reinstate the old alternate settings for that usb_interface
config->interface[i]? This was what my initial patch tried to do.
Alternatively usb_hcd_alloc_bandwidth() could undo what it does if an
error occurs there, then I think i could be decremented.
IOW isn't this the proper fix?
Roel
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 9bc95fe..4327eab 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1489,8 +1489,10 @@ reset_old_alts:
USB_REQ_SET_CONFIGURATION, 0,
config->desc.bConfigurationValue, 0,
NULL, 0, USB_CTRL_SET_TIMEOUT);
- if (retval < 0)
+ if (retval < 0) {
+ i--;
goto reset_old_alts;
+ }
mutex_unlock(&hcd->bandwidth_mutex);
/* re-init hc/hcd interface/endpoint state */
On Tue, Feb 09, 2010 at 05:01:53PM +0100, Roel Kluin wrote:
> After the loop `for (i = 0; i < config->desc.bNumInterfaces; i++)' if no
> break occurred, i equals config->desc.bNumInterfaces. so if
> usb_control_msg() failed then after goto reset_old_alts we read from
> config->interface[config->desc.bNumInterfaces].
> We can safely decrement i as well if the break occurred.
>
> Signed-off-by: Roel Kluin <[email protected]>
> Acked-by: Alan Stern <[email protected]>
Bah, yes, you're right. :) Good catch.
Signed-off-by: Sarah Sharp <[email protected]>
> ---
>
> > You correctly identified a problem, but your fix is wrong -- or at
> > least, it is much too complicated.
>
> Ok,
>
> drivers/usb/core/message.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
> index 9bc95fe..1a48aac 100644
> --- a/drivers/usb/core/message.c
> +++ b/drivers/usb/core/message.c
> @@ -1471,7 +1471,7 @@ int usb_reset_configuration(struct usb_device *dev)
> /* If not, reinstate the old alternate settings */
> if (retval < 0) {
> reset_old_alts:
> - for (; i >= 0; i--) {
> + for (i--; i >= 0; i--) {
> struct usb_interface *intf = config->interface[i];
> struct usb_host_interface *alt;
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Feb 9, 2010 at 11:01 PM, Sarah Sharp
<[email protected]> wrote:
> On Tue, Feb 09, 2010 at 05:01:53PM +0100, Roel Kluin wrote:
>> After the loop `for (i = 0; i < config->desc.bNumInterfaces; i++)' if no
>> break occurred, i equals config->desc.bNumInterfaces. so if
>> usb_control_msg() failed then after goto reset_old_alts we read from
>> config->interface[config->desc.bNumInterfaces].
>> We can safely decrement i as well if the break occurred.
>>
>> Signed-off-by: Roel Kluin <[email protected]>
>> Acked-by: Alan Stern <[email protected]>
>
> Bah, yes, you're right. :) Good catch.
Could you please confirm whether this patch is the better or the
other (in this same thread)?
Thanks,
Roel
On Tue, Feb 09, 2010 at 11:01:24PM +0100, Roel Kluin wrote:
> After the loop `for (i = 0; i < config->desc.bNumInterfaces; i++)' if no
> break occurred, i equals config->desc.bNumInterfaces. so if
> usb_control_msg() failed then after goto reset_old_alts we read from
> config->interface[config->desc.bNumInterfaces].
>
> Reported-by: "Juha Leppanen" <[email protected]>
> Signed-off-by: Roel Kluin <[email protected]>
> ---
>
> >> You correctly identified a problem, but your fix is wrong -- or at
> >> least, it is much too complicated. The proper fix goes like this:
> >
> > /* If not, reinstate the old alternate settings */
> > if (retval < 0) {
> > reset_old_alts:
> > - for (; i >= 0; i--) {
> > + for (i--; i >= 0; i--) {
> > struct usb_interface *intf = config->interface[i];
> > struct usb_host_interface *alt;
>
>
> Are you really sure this is better?
Yes.
> If usb_hcd_alloc_bandwidth() fails, in the loop _before_ the
> reset_old_alts label, don't we still have to reinstate the old
> alternate settings for that usb_interface config->interface[i]? This
> was what my initial patch tried to do.
No, you do not. Take a look at usb_hcd_alloc_bandwidth() in
drivers/usb/core/hcd.c. If an allocation fails for interface i when
the HCD's check_bandwidth() function is called, then
hcd->driver->reset_bandwidth is called. We only need to clean up the
interfaces that have successfully been allocated bandwidth (0 to i - 1).
> Alternatively usb_hcd_alloc_bandwidth() could undo what it does if an
> error occurs there, then I think i could be decremented.
Yes, that's what usb_hcd_alloc_bandwidth() does at the reset label.
Sarah
On Tue, Feb 09, 2010 at 11:09:45PM +0100, roel kluin wrote:
> On Tue, Feb 9, 2010 at 11:01 PM, Sarah Sharp
> <[email protected]> wrote:
> > On Tue, Feb 09, 2010 at 05:01:53PM +0100, Roel Kluin wrote:
> >> After the loop `for (i = 0; i < config->desc.bNumInterfaces; i++)' if no
> >> break occurred, i equals config->desc.bNumInterfaces. so if
> >> usb_control_msg() failed then after goto reset_old_alts we read from
> >> config->interface[config->desc.bNumInterfaces].
> >> We can safely decrement i as well if the break occurred.
> >>
> >> Signed-off-by: Roel Kluin <[email protected]>
> >> Acked-by: Alan Stern <[email protected]>
> >
> > Bah, yes, you're right. :) ?Good catch.
>
> Could you please confirm whether this patch is the better or the
> other (in this same thread)?
Can someone tell me which one is the correct one to apply, but resending
it to me?
thanks,
greg k-h
While looping over the interfaces, if usb_hcd_alloc_bandwidth() fails it calls
hcd->driver->reset_bandwidth(), so there was no need to reinstate the interface
again.
If no break occurred, the index equals config->desc.bNumInterfaces. A
subsequent usb_control_msg() failure resulted in a read from
config->interface[config->desc.bNumInterfaces] at label reset_old_alts.
In either case the last interface should be skipped.
Signed-off-by: Roel Kluin <[email protected]>
Acked-by: Alan Stern <[email protected]>
Acked-by: Sarah Sharp <[email protected]>
---
>> Could you please confirm whether this patch is the better or the
>> other (in this same thread)?
>
> Can someone tell me which one is the correct one to apply, but resending
> it to me?
This is the one as Sarah kindly explained to me.
Thanks, Roel
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 9bc95fe..1a48aac 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1471,7 +1471,7 @@ int usb_reset_configuration(struct usb_device *dev)
/* If not, reinstate the old alternate settings */
if (retval < 0) {
reset_old_alts:
- for (; i >= 0; i--) {
+ for (i--; i >= 0; i--) {
struct usb_interface *intf = config->interface[i];
struct usb_host_interface *alt;