Date:   Thu, 06 Jan 2022 10:34:01 +0100
Message-ID: <s5hr19lgqd2.wl-tiwai@suse.de>
From:   Takashi Iwai <tiwai@suse.de>
To:     Jiasheng Jiang <jiasheng@iscas.ac.cn>
Cc:     perex@perex.cz, tiwai@suse.com, leon@kernel.org,
        broonie@kernel.org, joe@perches.com, alsa-devel@alsa-project.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ALSA: intel_hdmi: Check for error num after setting mask
In-Reply-To: <20220106084110.2691207-1-jiasheng@iscas.ac.cn>
References: <20220106084110.2691207-1-jiasheng@iscas.ac.cn>
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On Thu, 06 Jan 2022 09:41:10 +0100,
Jiasheng Jiang wrote:
> 
> On Thu, Jan 06, 2022 at 04:18:01PM +0800, Takashi Iwai wrote:
> > Well, 32bit DMA mask practically never fails on x86 (and other
> > architectures, IIRC).  It's fine to add a sanity check, but it's
> > better to be mentioned that it never fails.
> 
> Actually, I have already found many place check the 32bit DMA mask.
> For example:
> snd_ad1889_create() in `sound/pci/ad1889.c`, 
> snd_vortex_create() in `sound/pci/au88x0/au88x0.c`
> tegra_pcm_dma_allocate() in `sound/soc/tegra/tegra_pcm.c`.
> Therefore, I think there must be some reason that 32bit may fail.
> So, to make the system more robust, it should be better to add the
> sanity check.

Yes, as mentioned, it's fine to add a sanity check, but it's rather
for consistency of the code, not actually fixing any real issue.
At least it's better to rephrase the commit message for avoiding
confusion for readers.


thanks,

Takashi