On 07/15/2010 07:10 AM, Alan Stern wrote:
Do you know exactly which code that is? Maybe the divisions can be removed or simplified. For example, see http://marc.info/?l=linux-usb&m=127911981822386&w=2
Oh, very very interesting!
So would I. However some EHCI hardware is buggy and requires the watchdog interrupt in order to run correctly. In recent kernels it is possible to turn off the watchdog interrupt for controllers that are known to be good. See the references to ehci->need_io_watchdog in ehci-pci.c:ehci_pci_setup().
I will have a look. We are not using PCI and as far as I know our controller should not have problems.
Yes, it is necessary. Otherwise an interrupt could cause some other driver to submit or cancel an URB while ehci_work is busy, leading to data corruption or a system hang.
In our case we disabled the interrupt line of the USB controller (that is not shared with other devices, in particular the audio device) and preliminary tests seem to be fine, but according to your statement it is only a disaster waiting to happen :) ???
bye as -- 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
