linux-kernel - [patch 0/4] media: Cleanup in

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Message-Id: <20201013142616.118697527@linutronix.de>
Date:   Tue, 13 Oct 2020 16:26:16 +0200
From:   Thomas Gleixner <tglx@...utronix.de>
To:     LKML <linux-kernel@...r.kernel.org>
Cc:     Peter Zijlstra <peterz@...radead.org>,
        Hans Verkuil <hverkuil@...all.nl>,
        Laurent Pinchart <laurent.pinchart@...asonboard.com>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        linux-media@...r.kernel.org, linux-usb@...r.kernel.org,
        Hans Verkuil <hverkuil-cisco@...all.nl>
Subject: [patch 0/4] media: Cleanup in_interrupt() usage

Folks,

in the discussion about preempt count consistency accross kernel
configurations:

 https://lore.kernel.org/r/20200914204209.256266093@linutronix.de/

it was concluded that the usage of in_interrupt() and related context
checks should be removed from non-core code.

The media subsystem has a few instances of in_interrupt() usage:

 1) BUG_ON(in_interrupt()

    BUG_ON() is considered the last resort and the usage there is clearly
    not in that category. It could be replaced by a
    lockdep_assert_preemption_enabled(), but all these usage sites invoke
    core functionality which will catch incorrect context already. So
    adding more there is not really useful

 2) Comments and printk()'s

    The comment is misleading and the checks in the printk()'s are
    pointless as the code can never be called from in_interrupt() as it
    contains GFP_KERNEL allocations.

I'm collecting related cleanups all over the tree, but feel free to route
them through the media tree as they have no dependencies. Let me know which
route you prefer.

Thanks,

	tglx
---
 common/saa7146/saa7146_fops.c |    2 --
 pci/bt8xx/bttv-risc.c         |    1 -
 pci/cx23885/cx23885-core.c    |    1 -
 pci/cx25821/cx25821-core.c    |    1 -
 platform/fsl-viu.c            |    2 --
 platform/omap3isp/ispccdc.c   |    5 ++---
 usb/au0828/au0828-video.c     |    5 ++---
 usb/cx231xx/cx231xx-core.c    |   10 ++++------
 usb/cx231xx/cx231xx-vbi.c     |    3 +--
 usb/tm6000/tm6000-video.c     |    2 --
 usb/zr364xx/zr364xx.c         |    2 --
 11 files changed, 9 insertions(+), 25 deletions(-)