Hi Adam, On Fri, Oct 4, 2019 at 12:39 PM Adam Ford <aford173@xxxxxxxxx> wrote: > > On Fri, Oct 4, 2019 at 5:02 AM Adam Ford <aford173@xxxxxxxxx> wrote: > > > > I am running Kernel 5.3.2 trying to troubleshoot some intermittent > > Bluetooth issues, and I think I have narrowed it down to the serial > > driver in use. > > I should have also noted that it's using UART2 with CTS and RTS on the > DM3730 (omap3630) and its configured with a baud rate of 3M. > I tried slowing it to 115200, but that didn't help. I tried disabling > the DMA hooks from the device tree, and that didn't help. > > > By default, omap2plus_defconfig enables both SERIAL_8250_OMAP and > > SERIAL_OMAP. I have my console device configured as ttyS0, and all > > appears fine. When I enable Bluetooth, however, I get intermittent > > errors on an DM3730 / OMAP3630. > > > > Using the 8250 driver for Blueotooth I get intermittent frame errors > > and data loss. > > > > Scanning ... > > [ 28.482452] Bluetooth: hci0: Frame reassembly failed (-84) > > [ 36.162170] Bluetooth: hci0: Frame reassembly failed (-84) > > F4:4E:FC:C9:2F:57 BluJax > > # l2ping F4:4E:FC:C9:2F:57 > > Ping: F4:4E:FC:C9:2F:57 from 00:18:30:49:7D:63 (data size 44) ... > > 44 bytes from F4:4E:FC:C9:2F:57 id 0 time 8.27ms > > no response from F4:4E:FC:C9:2F:57: id 1 > > ^C2 sent, 1 received, 50% loss > > > > (after a fairly long hang, I hit control-c) > > > > However, disabling the 8250 driver and using the only SERIAL_OMAP and > > the console routed to ttyO0, the Bluetooth works well, so I believe it > > to be a serial driver issue and not a Bluetooth error. > > > > # hcitool scan > > Scanning ... > > F4:4E:FC:C9:2F:57 BluJax > > ^C > > # l2ping F4:4E:FC:C9:2F:57 > > Ping: F4:4E:FC:C9:2F:57 from 00:18:30:49:7D:63 (data size 44) ... > > 44 bytes from F4:4E:FC:C9:2F:57 id 0 time 6.90ms > > ... > > 44 bytes from F4:4E:FC:C9:2F:57 id 14 time 28.29ms > > ^C15 sent, 15 received, 0% loss > > # > > > > 0% loss and regular, repeatable communication without any Frame > > reassembly errors. > > > > I tried disabling SERIAL_OMAP and using only SERIAL_8250_OMAP, but > that didn't help. Because the issue goes away when I disable > SERIAL_8250_OMAP, I am wondering if something is either being > misconfigured or some IRQ or DMA integration is missing that may be > present with the older SERIAL_OMAP driver. > > > Any suggestions on how to troubleshoot or what might cause the > > difference between the two drivers? Can it be related to this issue [1]? Can you confirm that 5.2 is working as expected with the 8250 driver? [1] https://marc.info/?l=linux-serial&m=156965039008649&w=2 Cheers, Yegor
