Dear Sarah, Thanks for the information. >> 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. > > What version of the code are you working with? My xhci-streams branch > does not have a function named xhci_free_streams_info(). It is xhci_free_stream_info(), but NOT xhci_free_streams_info(). Sorry for the TYPO. >> 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. > > I'm confused. If xhci_free_virt_device() got to freeing the streams, it > should also set xhci->devs[slot_id] to NULL. All calls to > xhci_free_virt_device() should be made while holding the xhci->lock. > With that assumption, xhci_free_streams() would exit early after > grabbing the lock and calling xhci_calculate_no_streams_bitmask(), which > will return early when it sees xhci->devs[slot_id] to be NULL. The API xhci_free_stream_info() is called from xhci_free_streams() API first, then it is called from xhci_free_virt_device(). I guess, the xhci_free_streams() would not exit early as the return value from the xhci_calculate_no_streams_bitmask() is not 0 as it does not see xhci->devs[slot_id] equals to NULL. >> 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. > > Please update to the latest streams branch and see if you still have > this issue. If you do, send me a patch that implements your fix > described above. I checked out the xhci-streams branch today with the following commands. # git clone git://git.kernel.org/pub/scm/linux/kernel/git/sarah/xhci.git # cd xhci # git checkout –b xhci-streams origin/xhci-streams The latest kernel version is 2.6.34-rc4. I saw the system crash with this kernel version also as the xhci_free_stream_info() API is called twice. Then, I commented the xhci_free_stream_info() API call in the xhci_free_streams() routine which is defined in the xhci.c file. After commenting this, everything seems to be working fine and I do not see any system crash. Please find the attached patch. Please let me know if there is anything wrong. Thanks and Regards, Ramya.
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xhci_free_stream_info-API-Commenting.patch
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