linux-kernel - Re: [PATCH 1/1] ARM: dts: Make DP a consumer of DISP1 power domain on Exynos5420

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]

Date:	Mon, 13 Apr 2015 19:59:11 +0900
From:	Krzysztof Kozlowski <k.kozlowski@...sung.com>
To:	Javier Martinez Canillas <javier.martinez@...labora.co.uk>
Cc:	Kukjin Kim <kgene@...nel.org>,
	Doug Anderson <dianders@...omium.org>,
	Olof Johansson <olof@...om.net>,
	Krzysztof Kozlowski <k.kozlowski@...sung.com>,
	Andrzej Hajda <a.hajda@...sung.com>,
	Kevin Hilman <khilman@...aro.org>,
	Tyler Baker <tyler.baker@...aro.org>,
	linux-arm-kernel@...ts.infradead.org,
	linux-samsung-soc@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/1] ARM: dts: Make DP a consumer of DISP1 power domain on Exynos5420

2015-04-13 5:30 GMT+09:00 Javier Martinez Canillas
<javier.martinez@...labora.co.uk>:
> Commit ea08de16eb1b ("ARM: dts: Add DISP1 power domain for exynos5420")
> added a device node for the Exynos5420 DISP1 power domain but dit not
> make the DP controller a consumer of that power domain.
>
> This causes an "Unhandled fault: imprecise external abort" error if the
> exynos-dp driver tries to access the DP controller registers and the PD
> was turned off. This lead to a kernel panic and a complete system hang.
>
> Make the DP controller device node a consumer of the DISP1 power domain
> to ensure that the PD is turned on when the exynos-dp driver is probed.
>
> Fixes: ea08de16eb1b ("ARM: dts: Add DISP1 power domain for exynos5420")
> Signed-off-by: Javier Martinez Canillas <javier.martinez@...labora.co.uk>
> ---
>
> Hello,
>
> This latent bug was not exposed before since drivers for other devices
> marked as DISP1 power domain consumers were probed before exynos-dp so
> the PD was already on which made possible to access the DP registers.
>
> But "regulator: Defer lookup of supply to regulator_get" [0] that is in
> linux-next from a couple of days now, changed the order on which the
> drivers' probes succeed so the PD was disabled during exynos-dp probe.
>
> Exynos5420 machines with a display such as the Exynos5420 Peach Pit and
> Exynos5800 Peach Pi were failing to boot due this issue, i.e: [1].
>
> Olof,
>
> Could you please confirm $subject fixes the issue catched by your farm?
>
> Krzysztof,
>
> This patch conflicts with your Exynos5 phandle notation cleanup [2] but
> I preferred to send it on top of linux-next instead of making your series
> a dependency since it fixes a very important bug that had caused -next to
> be broken on these matchines for days now.

Sure, I don't mind. My patchset is just a cleanup so it can wait and
should not block important stuff.

Best regards,
Krzysztof
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/