Re: [PATCH 12/21] ata: libahci: Discard redundant force_port_map parameter

From: Damien Le Moal
Date: Mon Apr 11 2022 - 18:49:07 EST


On 4/12/22 05:52, Serge Semin wrote:
> On Mon, Apr 11, 2022 at 09:25:03PM +0900, Damien Le Moal wrote:
>> On 4/11/22 21:11, Serge Semin wrote:
>>> On Thu, Mar 24, 2022 at 11:05:58AM +0900, Damien Le Moal wrote:
>>>> On 3/24/22 09:16, Serge Semin wrote:
>>>>> Currently there are four port-map-related fields declared in the
>>>>> ahci_host_priv structure and used to setup the HBA ports mapping. First
>>>>> the ports-mapping is read from the PI register and immediately stored in
>>>>> the saved_port_map field. If forced_port_map is initialized with non-zero
>>>>> value then its value will have greater priority over the value read from
>>>>> PI, thus it will override the saved_port_map field. That value will be then
>>>>> masked by a non-zero mask_port_map field and after some sanity checks it
>>>>> will be stored in the ahci_host_priv.port_map field as a final port
>>>>> mapping.
>>>>>
>>>>> As you can see the logic is a bit too complicated for such a simple task.
>>>>> We can freely get rid from at least one of the fields with no change to
>>>>> the implemented semantic. The force_port_map field can be replaced with
>>>>> taking non-zero saved_port_map value into account. So if saved_port_map is
>>>>> pre-initialized by the glue-driver/platform-specific code then it will
>>>>
>>>
>>>> glue-driver == LLDD (low level device driver), for the entire series please.
>>>
>>> Why? It's a normal term and well known amongst developers. I've used it
>>> in a plenty of my patches before and none of them has been questioned in that
>>> part so far.
>>
>
>> This term is not used in libata, nor do I remember seeing it used in SCSI
>> or block subsystem either. We always talk about mid-layer (ahci platform)
>> and LLDD (adapter driver).
>
> Great, do we need to learn the subsystem-specific dictionary now
> before submitting the patches for it? =)
> Really, you are asking me to change one term to its synonym just
> because it's mainly unused here. Now you know what it means, the
> others can easily google it and get to learn something new. Win-win.)

I already knew what it meant, but it was unclear if my idea of what you
meant was actually the same as yours. Sticking with the vocabulary already
used since *a long time ago* makes life easier for reviewers and avoids
confusion.

--
Damien Le Moal
Western Digital Research