From: Martin Sperl <kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>
To: Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>,
Lee Jones <lee-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-rpi-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
Subject: Re: [PATCH V2] spi: bcm2835: enabling polling mode for transfers shorter than 30us
Date: Sat, 18 Apr 2015 14:13:56 +0200 [thread overview]
Message-ID: <EB2DE44C-29CA-422D-A89C-4173E02A2CEF@martin.sperl.org> (raw)
In-Reply-To: <20150418115343.GI26185-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
> On 18.04.2015, at 13:53, Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> wrote:
>
> As I've said several times now 1s seems far too long for a busy wait,
> the driver should fall back to something that sleeps after an initial
> busy wait (once it's clear we're over time).
Then I have misread what you wrote - I understood you wanted to avoid
having no timeout at all.
So you want something like:
* wait for 4 jiffies (which is 40ms typically)
* if we exceed that, then enable interrupts for the rest of the transfer
and let the 30s timeout handle everything else
Martin
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next prev parent reply other threads:[~2015-04-18 12:13 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-06 17:16 [PATCH V2] spi: bcm2835: enabling polling mode for transfers shorter than 30us kernel-TqfNSX0MhmxHKSADF0wUEw
[not found] ` <1428340592-3196-1-git-send-email-kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>
2015-04-10 18:51 ` Mark Brown
[not found] ` <20150410185132.GU6023-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2015-04-14 14:29 ` Martin Sperl
[not found] ` <F35B7C71-1917-40AE-BA42-CB3E63B877EF-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>
2015-04-15 18:58 ` Mark Brown
[not found] ` <20150415185824.GU6023-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2015-04-15 19:33 ` Martin Sperl
[not found] ` <262B0C8C-7728-458E-8748-06F79251BE0C-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>
2015-04-18 10:42 ` Mark Brown
[not found] ` <20150418104202.GA26185-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2015-04-18 11:12 ` Martin Sperl
[not found] ` <54169601-55F7-464C-8A0E-ABF833C0F3BA-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>
2015-04-18 11:53 ` Mark Brown
[not found] ` <20150418115343.GI26185-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2015-04-18 12:13 ` Martin Sperl [this message]
[not found] ` <EB2DE44C-29CA-422D-A89C-4173E02A2CEF-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>
2015-04-18 12:27 ` Mark Brown
[not found] ` <20150418122748.GO26185-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2015-04-18 13:31 ` Martin Sperl
[not found] ` <2DB27253-8254-4098-ADE3-9AA22D52BE9D-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>
2015-04-18 17:07 ` Mark Brown
[not found] ` <20150418170756.GX26185-GFdadSzt00ze9xe1eoZjHA@public.gmane.org>
2015-04-19 9:44 ` Martin Sperl
[not found] ` <E9247B42-11B6-4032-A6C1-1FCEA3EDA2A6-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>
2015-04-22 7:33 ` [PATCH] spi: bcm2835: fallback to interrupt for polling timeouts exceeding 2 jiffies kernel-TqfNSX0MhmxHKSADF0wUEw
[not found] ` <1429687984-7350-1-git-send-email-kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org>
2015-04-22 19:50 ` Mark Brown
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