public inbox for linux-mtd@lists.infradead.org
 help / color / mirror / Atom feed
From: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
To: David Woodhouse <dwmw2@infradead.org>
Cc: linux-mtd@lists.infradead.org, dedekind1@gmail.com
Subject: Re: [PATCH] [MTD] Adjust the NOR CFI flash timeouts to round better
Date: Mon, 15 Oct 2012 13:08:13 -0600	[thread overview]
Message-ID: <20121015190813.GA7638@obsidianresearch.com> (raw)
In-Reply-To: <1350325973.14124.49.camel@shinybook.infradead.org>

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=unknown-8bit, Size: 1122 bytes --]

On Mon, Oct 15, 2012 at 11:32:53AM -0700, David Woodhouse wrote:

> Yes, HZ/1500+1 I could understand. That's the number of jiffies that
> give you '666µs or more'. The +2 is odd though.

Looking more closely I agree, it seems bogus - the use of time_after
takes care of the short first jiffy problem, the real problem I see is
that 1500 was supposed to be µs, that is close to the datasheet spec
for the flash I have. Fixing that will almost double the timeout on my
systems...

> > > I'd like someone with infinite amounts of free time to go through and
> > > clean them all up :)
> > 
> > lol! Would you accept msecs_to_jiffies conversion for the cfi files?
> 
> Absolutely. Although I'd like to take a little step back and take a more
> thoughtful view of how we *should* be handing these timeouts, rather
> than a simple janitor-style conversion of the existing code.

Okay, well, I'll send a patch in a few days, if there is a better way
than:

 unsigned long uWriteTimeout = usecs_to_jiffies(1500);
 timeo = jiffies + uWriteTimeout;
 if (time_after(jiffies, timeo)) // TIMEOUT

Maybe someone will pipe up?

Jason

  reply	other threads:[~2012-10-15 19:08 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-05 18:32 [PATCH] [MTD] Adjust the NOR CFI flash timeouts to round better Jason Gunthorpe
2012-10-15 13:42 ` Artem Bityutskiy
2012-10-15 16:09   ` David Woodhouse
2012-10-15 16:57     ` Jason Gunthorpe
2012-10-15 17:31       ` David Woodhouse
2012-10-15 17:49         ` Jason Gunthorpe
2012-10-15 18:32           ` David Woodhouse
2012-10-15 19:08             ` Jason Gunthorpe [this message]
2012-10-15 19:28     ` Artem Bityutskiy
2012-10-15 20:00       ` David Woodhouse

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=20121015190813.GA7638@obsidianresearch.com \
    --to=jgunthorpe@obsidianresearch.com \
    --cc=dedekind1@gmail.com \
    --cc=dwmw2@infradead.org \
    --cc=linux-mtd@lists.infradead.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