Re: [PATCH] serial: of-serial: Remove device_type = "serial" registration

[Michal Simek]

On 04/14/2015 09:38 AM, Greg Kroah-Hartman wrote:
> On Tue, Apr 14, 2015 at 07:10:07AM +0200, Michal Simek wrote:
>> Hi Greg,
>>
>> On 04/13/2015 07:00 PM, Greg Kroah-Hartman wrote:
>>> On Mon, Apr 13, 2015 at 04:35:27PM +0200, Michal Simek wrote:
>>>> Do not probe all serial drivers by of_serial.c which are using
>>>> device_type = "serial"; property. Only drivers which have valid
>>>> compatible strings listed in the driver should be probed.
>>>
>>> Why?  This was added for some reason, what has changed since then?
>>
>> I was discussing this patch with Arnd over IRC.
>>
>> This is what Arnd was saying yesterday.
>> "when I wrote that driver initially, the idea was that it would get used
>> as a stub to hook up all other serial drivers
>> but after that, the common code learned to create platform devices from DT"
>>
>> and resolution from our discussion was to remove this line because make
>> no sense to probe all drivers which has device_type = "serial".
>> It was causing the problem on one system with xilinx_uartps and 16550a
>> IP where of_serial failed to register for xilinx_uartps and because of
>> irq_dispose_mapping removed irq_desc. Then when xilinx_uartps was asking
>> for irq with request_irq() it was returning EINVAL.
>>
>> The first problem was that of_serial tried to bind driver because of
>> device_type = "serial"; and the second problem was in xilinx_uartps
>> driver by incorrectly using platform_get_resources() which doesn't
>> create irq mapping which is fixed by the second patch.
> 
> All of this should have been in the patch description, as we have no
> idea what your irc conversation was.
> 
> Please fix up and resend.

I have extend patch description and sent v2.

Thanks,
Michal


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