[PATCH] arm64: add support for uart earlyprintk

Marc Zyngier marc.zyngier at arm.com
Thu Feb 28 07:52:20 EST 2013


On 28/02/13 12:10, Catalin Marinas wrote:
> On Thu, Feb 28, 2013 at 11:34:17AM +0000, Marc Zyngier wrote:
>> On 28/02/13 11:01, Anup Patel wrote:
>>> +}
>>> +
>>> +/*
>>>   * PL011 single character TX.
>>>   */
>>>  static void pl011_printch(char ch)
>>> @@ -47,6 +62,7 @@ struct earlycon_match {
>>>  
>>>  static const struct earlycon_match earlycon_match[] __initconst = {
>>>  	{ .name = "pl011", .printch = pl011_printch, },
>>> +	{ .name = "uart", .printch = uart_printch, },
>>
>> "uart" is way too generic. pl011 is an UART too, and I suspect most of
>> the backends that are going to be added here over time will be UARTs.
>>
>> "uart8250" would be a possibility (and actually consistent with the rest
>> of the kernel, see drivers/tty/serial/8250/8250_early.c.
> 
> I think it makes more sense to use the existing 8250_early.c driver. It
> has more features than the simple earlyprintk implementation in the
> 64-bit kernel (like parsing more parameters, initialising the UART). The
> only difference is that the early_param is called "earlycon".

Indeed, this seems to be the best way, as it removes the need for this
patch altogether.

	M.
-- 
Jazz is not dead. It just smells funny...




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