From: garsilva@embeddedor.com (Gustavo A. R. Silva)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] spi: bcm2835aux: use 64-bit arithmetic instead of 32-bit
Date: Mon, 12 Feb 2018 11:57:20 -0600 [thread overview]
Message-ID: <c3e615e4-5c2d-4c3c-0417-5c04230bd5e5@embeddedor.com> (raw)
In-Reply-To: <87inb7c2ld.fsf@anholt.net>
Hi Eric,
On 02/08/2018 02:22 AM, Eric Anholt wrote:
> "Gustavo A. R. Silva" <gustavo@embeddedor.com> writes:
>
>> Add suffix ULL to constant 9 in order to give the compiler complete
>> information about the proper arithmetic to use. Notice that this
>> constant is used in a context that expects an expression of type
>> unsigned long long (64 bits, unsigned).
>>
>> The expression tfr->len * 9 * 1000000 is currently being evaluated
>> using 32-bit arithmetic.
>>
>> Addresses-Coverity-ID: 1339619
>> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
>
> The effect looks like it would be that we would have chosen polling mode
> instead of waiting for interrupts for some transfers >477 seconds.
> Seems like a good fix for an unlikely bug.
>
> Reviewed-by: Eric Anholt <eric@anholt.net>
>
Thank you for your review.
--
Gustavo
next prev parent reply other threads:[~2018-02-12 17:57 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-07 16:00 [PATCH] spi: bcm2835aux: use 64-bit arithmetic instead of 32-bit Gustavo A. R. Silva
2018-02-08 8:22 ` Eric Anholt
2018-02-12 17:57 ` Gustavo A. R. Silva [this message]
2018-02-08 9:54 ` Ard Biesheuvel
2018-02-12 18:04 ` Gustavo A. R. Silva
2018-02-12 18:45 ` Ard Biesheuvel
2018-02-12 19:10 ` Florian Fainelli
2018-02-12 19:11 ` Ard Biesheuvel
2018-02-12 19:14 ` Florian Fainelli
2018-02-12 19:31 ` Trent Piepho
2018-02-12 19:38 ` [PATCH] spi: bcm2835aux: Avoid 64-bit arithmetic in xfer len calc Trent Piepho
2018-02-14 16:04 ` Mark Brown
2018-02-14 16:28 ` Applied "spi: bcm2835aux: Avoid 64-bit arithmetic in xfer len calc" to the spi tree Mark Brown
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=c3e615e4-5c2d-4c3c-0417-5c04230bd5e5@embeddedor.com \
--to=garsilva@embeddedor.com \
--cc=linux-arm-kernel@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;
as well as URLs for NNTP newsgroup(s).