Re: [RFC PATCH v2 2/2] serial: imx: Switch to nbcon console

[Esben Haabendal <esben@geanix.com>]

John Ogness <john.ogness@linutronix.de> writes:

> In your imx_uart_console_write_atomic() I see lots of register usage:
>
> ucr1, ucr2, ucr3, usr2, uts
>
> It is critical that _all_ usage of these registers throughout the driver
> is protected, preferably protected by the port lock. Please go through
> and verify that. If imx_uart_console_write_thread() is using even more
> registers, you will need to check those as well.

The _write_thread() uses only the same registers.

> For the 8250 I went through all uses and found several problems [0]. The
> imx driver may have similar issues.

I have now gone through all usage of above mentioned registers in the
driver. I found a single missing lock/unlock, but other than that the
driver seems to be in good shape in this regards.

In the _probe() function, the following registers are accessed
unprotected: ucr1, ucr2, ucr3, uts. But I assume this should be safe, as
the uart port is not registred yet, and interrupt handlers have not been
registered.

I will send out a v3 short, hoping we can get this in a shape where we
can get it merged shortly after the 8250 driver nbcon patches.

/Esben