On Sat, Apr 24, 2010 at 8:42 PM, Greg KH <greg@xxxxxxxxx> wrote: > On Sat, Apr 24, 2010 at 03:02:57PM +0530, Ramya Desai wrote: >> Dear Experts, >> >> My system crashes when I use the usb_free_streams API in my driver >> code. The usb_free_streams API is executed correctly without any >> issue, but after some time, around 1 minute, I saw the trace when I >> type dmesg. If I comment this API, there is no crash and I am able to >> all the operations with my driver. I am using the usb_alloc_streams >> API in the driver initialization routine (probe method, when device >> inserted) and usb_free_streams API in the driver exit routine (release >> method, when device removed). >> >> I am working on Ubuntu with 2.6.34-rc2 kernel. It also crashes in >> 2.6.32 kernel version. I do not understand, why it crashes when I use >> the API. >> >> Any ideas / suggestions are greatly appreciated. > > Can you duplicate this without the closed source, nvidia driver loaded? Dea Greg, The driver seems to be working fine and there is no system crash when I comment the API named, xhci_free_streams_info(), in the xhci_free_streams() routine which is defined in the xhci.c file. This is because, the same API is called from xhci_free_virt_device() routine which is defined in xhci-mem.c file. When it is called twice, I saw the following messages (3 times) in the kernel log. xhci_hcd 0000:06:00.0: dma_pool_free xHCI input/output contexts, 7269762f/6c617574 (bad dma) If I do not call usb_free_streams API, the xhci_free_streams_info() is called only one time from the from xhci_free_virt_device() routine. This time, I did not see any "bad dma" messages in the kernel log. So, I just commented the xhci_free_streams_info() API call in the xhci_free_streams() routine. After, commenting this, every thing seems to be working fine. Please let me know If this is the right way of doing it. Thanks and Regards, Ramya. -- 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
