Re: [PATCH 1/2] serial: samsung: Move uart_register_driver call todevice probe

From: Tushar Behera
Date: Mon Jan 20 2014 - 06:53:28 EST

On 20 January 2014 15:35, Russell King - ARM Linux
<linux@xxxxxxxxxxxxxxxx> wrote:
> On Mon, Jan 20, 2014 at 02:32:34PM +0530, Tushar Behera wrote:
>> uart_register_driver call binds the driver to a specific device
>> node through tty_register_driver call. This should typically happen
>> during device probe call.
>> In a multiplatform scenario, it is possible that multiple serial
>> drivers are part of the kernel. Currently the driver registration fails
>> if multiple serial drivers with same default major/minor numbers are
>> included in the kernel.
>> A typical case is observed with amba-pl011 and samsung-uart drivers.
> The samsung-uart driver is at fault here - the major/minor numbers were
> officially registered to amba-pl011. Samsung needs to be fixed properly.

I had earlier submitted a patch [1] to remove the hard coded
major/minor number for Samsung UART driver, but that was rejected
because of userspace breakage. Without this patch, Samsung UART driver
can't bind to the hard-coded device node. Changing the default
major/minor will also not help to fix the objections raised in [1].

Would you please suggest a way forward?


Tushar Behera
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at