linux-kernel - Re: [PATCH v2] regmap: irq: fix ack-invert

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20180306145749.GC5799@atomide.com>
Date:   Tue, 6 Mar 2018 06:57:49 -0800
From:   Tony Lindgren <tony@...mide.com>
To:     Tim Harvey <tharvey@...eworks.com>
Cc:     linux-kernel@...r.kernel.org, Mark Brown <broonie@...nel.org>,
        Benjamin Gaignard <benjamin.gaignard@...aro.org>,
        Lee Jones <lee.jones@...aro.org>, Guo Zeng <Guo.Zeng@....com>
Subject: Re: [PATCH v2] regmap: irq: fix ack-invert

Hi,

* Tim Harvey <tharvey@...eworks.com> [180305 20:59]:
> When acking irqs we need to take into account the ack-invert case.
> Without this chips that require 0's to ACK interrupts will never clear
> the interrupt.
> 
> By using regmap_irq_update_bits to ACK the interrupts we use the masked
> status bits so we take care not to affect any other bits then use
> ack_invert to determine if we clear or set those bits.

This change to use regmap_irq_update_bits() now breaks things for
me with cpcap interrupts. So it seems to cause a non-inverted mode
regression. There should be no need to read the ack register, I
gues that's the whole idea of having a separate ack register :)

> The only user of ack_invert currently appears to be the motorola-cpcap
> driver which we find is incorrectly setting ack_invert and thus we
> fix that at the same time as otherwise it would break.

Regards,

Tony