linux-kernel - Re: [PATCH v3] drm/v3d/v3d_drv: Fix PM disable depth imbalance

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: <Ypd76wmrBsIgeE3O@orome>
Date:   Wed, 1 Jun 2022 16:47:07 +0200
From:   Thierry Reding <thierry.reding@...il.com>
To:     Miaoqian Lin <linmq006@...il.com>
Cc:     Emma Anholt <emma@...olt.net>, David Airlie <airlied@...ux.ie>,
        Eric Anholt <eric@...olt.net>, dri-devel@...ts.freedesktop.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3] drm/v3d/v3d_drv: Fix PM disable depth imbalance

On Wed, Jun 01, 2022 at 09:55:02PM +0800, Miaoqian Lin wrote:
> Hi, Daniel
> 
> On 2022/6/1 21:26, Daniel Vetter wrote:
> > On Wed, Jun 01, 2022 at 04:20:50PM +0400, Miaoqian Lin wrote:
> >> The pm_runtime_enable will increase power disable depth.
> >> If the probe fails, we should use pm_runtime_disable() to balance
> >> pm_runtime_enable().
> >> Also call disable function in remove function.
> >>
> >> Fixes: 57692c94dcbe ("drm/v3d: Introduce a new DRM driver for Broadcom V3D V3.x+")
> >> Signed-off-by: Miaoqian Lin <linmq006@...il.com>
> >> ---
> >> Changes in v3:
> >> - call pm_runtime_disable() in v3d_platform_drm_remove
> >> - update commit message
> >>
> >> Changes in v2
> >> - put pm_runtime_disable before dma_free_wc
> >> - rename dma_free to pm_disable
> >>
> >> v1: https://lore.kernel.org/r/20220105120442.14418-1-linmq006@gmail.com
> >> v2: https://lore.kernel.org/r/20220106124657.32737-1-linmq006@gmail.com
> > Maybe a bit late since we're at v3 already, but are there no devm_
> > functions here that would dtrt automatically? 
> 
> Sorry I don't see one, or we can use devm_add_action_or_reset() to add handling
> 
> action. something like disp_cc_sm8250_probe() in drivers/clk/qcom/dispcc-sm8250.c
> 
> How do you think?

Looks like there's a devm_pm_runtime_enable() helper that does exactly
that. See commit b3636a3a2c51 ("PM: runtime: add devm_pm_runtime_enable
helper"). I haven't seen any large janitorial series yet for that, so
perhaps it's just not widely known yet.

Thierry

Download attachment "signature.asc" of type "application/pgp-signature" (834 bytes)