From: Peter Hurley <peter@hurleysoftware.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, linux-next@vger.kernel.org,
linux-serial@vger.kernel.org, Rob Herring <robh@kernel.org>,
Yinghai Lu <yinghai@kernel.org>
Subject: Re: [PATCH v3] earlycon: 8250: Fix command line regression
Date: Sat, 04 Apr 2015 13:08:42 -0400 [thread overview]
Message-ID: <55201A9A.3080102@hurleysoftware.com> (raw)
In-Reply-To: <20150404165217.GA26861@kroah.com>
On 04/04/2015 12:52 PM, Greg Kroah-Hartman wrote:
> On Sat, Apr 04, 2015 at 12:23:14PM -0400, Peter Hurley wrote:
>> On 04/04/2015 12:09 PM, Greg Kroah-Hartman wrote:
>>> On Sat, Apr 04, 2015 at 10:27:30AM -0400, Peter Hurley wrote:
[...]
>>>> +/* FIXME: this is broken on most other 8250 h/w */
>>>
>>> What do you mean by "most other"? What hardware does this work for?
>>> What is it broken for? What is someone supposed to think/do with this
>>> comment?
>>
>> It's a direct copy of the existing behavior for 8250 earlycon, which is
>> broken for h/w with non-standard divisor registers. That's basically
>> _every_ new design, because that's what vendors need to extend to support
>> modern bitrates.
>>
>> Affected h/w that I know of includes: 8250_dw, exar xr17v35 cards, omap8250,
>> omap15xx, intel byt, intel mid.
>>
>> But it was already broken for these and so not a regression.
>
> Sorry, I know the function is a copy, you haven't broken anything that
> wasn't already broken. I see this comment as a "rant", but we might as
> well turn that "rant" into something descriptive to let other people
> know what is really going on here.
It's not intended as rant. My concern is that it appears as "desirable"
code because it's new, when that's not my intention.
When others go to implement earlycon-to-console handoff, my hope is
that they don't follow this exemplar. Unfortunately, since this is
the only driver that implements earlycon-to-console handoff (right now),
some might just simply copy the behavior here. My intention is to
discourage that.
> Sound reasonable?
Ok. How about "most new"?
Regards,
Peter Hurley
prev parent reply other threads:[~2015-04-04 17:08 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1428105875-4038-1-git-send-email-peter@hurleysoftware.com>
2015-04-04 14:27 ` [PATCH v3] earlycon: 8250: Fix command line regression Peter Hurley
2015-04-04 16:09 ` Greg Kroah-Hartman
2015-04-04 16:23 ` Peter Hurley
2015-04-04 16:52 ` Greg Kroah-Hartman
2015-04-04 17:08 ` Peter Hurley [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=55201A9A.3080102@hurleysoftware.com \
--to=peter@hurleysoftware.com \
--cc=akpm@linux-foundation.org \
--cc=gregkh@linuxfoundation.org \
--cc=jslaby@suse.cz \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-next@vger.kernel.org \
--cc=linux-serial@vger.kernel.org \
--cc=robh@kernel.org \
--cc=yinghai@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox