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Date:   Wed, 20 Nov 2019 19:07:33 +0100
From:   Borislav Petkov <bp@alien8.de>
To:     thor.thayer@linux.intel.com
Cc:     stable@vger.kernel.org, mchehab@kernel.org, tony.luck@intel.com,
        james.morse@arm.com, rrichter@marvell.com,
        linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org,
        Meng Li <Meng.Li@windriver.com>
Subject: Re: [PATCH] EDAC/altera: Use fast register IO for S10 IRQs
Message-ID: <20191120180733.GJ2634@zn.tnic>
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On Wed, Nov 20, 2019 at 11:38:01AM -0600, thor.thayer@linux.intel.com wrote:
> From: Thor Thayer <thor.thayer@linux.intel.com>
> 
> When an irq occurs in altera edac driver, regmap_xxx() is invoked
> in atomic context. Regmap must indicate register IO is fast so
> that a spinlock is used instead of a mutex to avoid sleeping
> in atomic context.
> 
> Fixes mutex-lock error
>    lock_acquire+0xfc/0x288
>    __mutex_lock+0x8c/0x808
>    mutex_lock_nested+0x3c/0x50
>    regmap_lock_mutex+0x24/0x30
>    regmap_write+0x40/0x78
>    a10_eccmgr_irq_unmask+0x34/0x40
>    unmask_irq.part.0+0x30/0x50
>    irq_enable+0x74/0x80
>    __irq_startup+0x80/0xa8
>    irq_startup+0x70/0x150
>    __setup_irq+0x650/0x6d0
>    request_threaded_irq+0xe4/0x180
>    devm_request_threaded_irq+0x7c/0xf0
>    altr_sdram_probe+0x2c4/0x600
> <snip>
> 
> Upstream fix pending [1] (common code uses fast mode)
> [1] https://lkml.org/lkml/2019/11/7/1014

I don't understand - I picked those up and are already queued for 5.5:

https://git.kernel.org/pub/scm/linux/kernel/git/ras/ras.git/log/?h=edac-for-next

What is that patch for?

Are you saying, I should stick it before the two patches above so that
it gets backported to stable so that you have older kernels addressed?

But then the above ones won't apply anymore because

EDAC/altera: Use the Altera System Manager driver

removes s10_sdram_regmap_cfg.

What I can offer you is to remove the two patches and apply this one so
that it goes in next week. Then, you can send me the two rediffed after
5.5-rc1 is out. Ok?

> Fixes: 3dab6bd52687 ("EDAC, altera: Add support for Stratix10 SDRAM EDAC")
> Cc: stable@vger.kernel.org
> Reported-by: Meng Li <Meng.Li@windriver.com>
> Signed-off-by: Meng Li <Meng.Li@windriver.com>

What does Meng's SOB mean?

> Signed-off-by: Thor Thayer <thor.thayer@linux.intel.com>

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette