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3611f4d2a5
Arjan: With the help of kerneloops.org I've spotted a nice little interaction between the TTY layer and the bluetooth code, however the tty layer is not something I'm all too familiar with so I rather ask than brute-force fix the code incorrectly. The raw details are at: http://www.kerneloops.org/search.php?search=uart_flush_buffer What happens is that, on closing the bluetooth tty, the tty layer goes into the release_dev() function, which first does a bunch of stuff, then sets the file->private_data to NULL, does some more stuff and then calls the ldisc close function. Which in this case, is hci_uart_tty_close(). Now, hci_uart_tty_close() calls hci_uart_close() which clears some internal bit, and then calls hci_uart_flush()... which calls back to the tty layers' uart_flush_buffer() function. (in drivers/bluetooth/hci_tty.c around line 194) Which then WARN_ON()'s because that's not allowed/supposed to be called this late in the shutdown of the port.... Should the bluetooth driver even call this flush function at all?? David: This seems to be what happens: Hci_uart_close() flushes using hci_uart_flush(). Subsequently, in hci_dev_do_close(), (one step in hci_unregister_dev()), hci_uart_flush() is called again. The comment in uart_flush_buffer(), relating to the WARN_ON(), indicates you can't flush after the port is closed; which sounds reasonable. I think hci_uart_close() should set hdev->flush to NULL before returning. Hci_dev_do_close() does check for this. The code path is rather involved and I'm not entirely clear of all steps, but I think that's what should be done. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net> |
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| acorn/char | ||
| acpi | ||
| amba | ||
| ata | ||
| atm | ||
| auxdisplay | ||
| base | ||
| block | ||
| bluetooth | ||
| cdrom | ||
| char | ||
| clocksource | ||
| connector | ||
| cpufreq | ||
| cpuidle | ||
| crypto | ||
| dca | ||
| dio | ||
| dma | ||
| edac | ||
| eisa | ||
| firewire | ||
| firmware | ||
| gpio | ||
| hid | ||
| hwmon | ||
| i2c | ||
| ide | ||
| ieee1394 | ||
| infiniband | ||
| input | ||
| isdn | ||
| leds | ||
| lguest | ||
| macintosh | ||
| mca | ||
| md | ||
| media | ||
| memstick | ||
| message | ||
| mfd | ||
| misc | ||
| mmc | ||
| mtd | ||
| net | ||
| nubus | ||
| of | ||
| oprofile | ||
| parisc | ||
| parport | ||
| pci | ||
| pcmcia | ||
| pnp | ||
| power | ||
| ps3 | ||
| rapidio | ||
| rtc | ||
| s390 | ||
| sbus | ||
| scsi | ||
| serial | ||
| sh | ||
| sn | ||
| spi | ||
| ssb | ||
| tc | ||
| telephony | ||
| thermal | ||
| uio | ||
| usb | ||
| video | ||
| virtio | ||
| w1 | ||
| watchdog | ||
| xen | ||
| zorro | ||
| Kconfig | ||
| Makefile | ||