I started out this series trying to make sysrq work over the serial console on qcom_geni_serial, then fell into a rat's nest. To solve the deadlock I faced when enabling sysrq I tried to borrow code from '8250_port.c' which avoided grabbing the port lock in console_write(). ...but since these days I try to run with lockdep on all the time, I found it caused an annoying lockdep splat (which I also reproduced on my rk3399 board). ...so I instead changed my qcom_geni_serial solution to borrow code from 'msm_serial.c' I wasn't super happy with the solution in 'msm_serial.c' though. I don't like releasing the spinlock there. Not only is it ugly but it means we are unlocking / re-locking _all the time_ even though sysrq characters are rare. ...so I came up with what I think is a better solution and then implemented it for qcom_geni_serial. Since I had a good way to test 8250-based UARTs, I also fixed that driver to use my new method. When doing so, I ran into a missing msm_serial.c at all, so I didn't switch that (or all other serial drivers for that matter) to the new method. After fixing all the above issues, I found the next lockdep splat in kgdb and I think I've worked around it in a good-enough way, but I'm much less confident about this. Hopefully folks can take a look at it. In general, patches earlier in this series should be "less controversial" and hopefully can land even if people don't like patches later in the series. ;-) Looking back, this is pretty much two series squashed that could be treated indepdently. The first is a serial series and the second is a kgdb series. For all serial patches I'd expect them to go through the tty tree once they've been reviewed. If folks are OK w/ the 'smp' patch it probably should go in some core kernel tree. The kgdb patch won't work without it, though, so to land that we'd need coordination between the folks landing that and the folks landing the 'smp' patch. Douglas Anderson (7): serial: qcom_geni_serial: Finish supporting sysrq serial: core: Allow processing sysrq at port unlock time serial: qcom_geni_serial: Process sysrq at port unlock time serial: core: Include console.h from serial_core.h serial: 8250: Process sysrq at port unlock time smp: Don't yell about IRQs disabled in kgdb_roundup_cpus() kgdb: Remove irq flags and local_irq_enable/disable from roundup arch/arc/kernel/kgdb.c | 4 +-- arch/arm/kernel/kgdb.c | 4 +-- arch/arm64/kernel/kgdb.c | 4 +-- arch/hexagon/kernel/kgdb.c | 11 ++---- arch/mips/kernel/kgdb.c | 4 +-- arch/powerpc/kernel/kgdb.c | 2 +- arch/sh/kernel/kgdb.c | 4 +-- arch/sparc/kernel/smp_64.c | 2 +- arch/x86/kernel/kgdb.c | 9 ++--- drivers/tty/serial/8250/8250_aspeed_vuart.c | 6 +++- drivers/tty/serial/8250/8250_fsl.c | 6 +++- drivers/tty/serial/8250/8250_omap.c | 6 +++- drivers/tty/serial/8250/8250_port.c | 8 ++--- drivers/tty/serial/qcom_geni_serial.c | 10 ++++-- include/linux/kgdb.h | 9 ++--- include/linux/serial_core.h | 38 ++++++++++++++++++++- kernel/debug/debug_core.c | 2 +- kernel/smp.c | 4 ++- 18 files changed, 80 insertions(+), 53 deletions(-) -- 2.19.1.568.g152ad8e336-goog
