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Date:   Tue, 11 Feb 2020 20:15:12 +0100
Message-ID: <s5hlfp90wcf.wl-tiwai@suse.de>
From:   Takashi Iwai <tiwai@suse.de>
To:     Arvind Sankar <nivedita@alum.mit.edu>
Cc:     Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>,
        <alsa-devel@alsa-project.org>, <linux-usb@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] ALSA: usb-audio: Apply sample rate quirk for Audioengine D1
In-Reply-To: <20200211162235.1639889-1-nivedita@alum.mit.edu>
References: <20200211162235.1639889-1-nivedita@alum.mit.edu>
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On Tue, 11 Feb 2020 17:22:35 +0100,
Arvind Sankar wrote:
> 
> The Audioengine D1 (0x2912:0x30c8) does support reading the sample rate,
> but it returns the rate in byte-reversed order.
> 
> When setting sampling rate, the driver produces these warning messages:
> [168840.944226] usb 3-2.2: current rate 4500480 is different from the runtime rate 44100
> [168854.930414] usb 3-2.2: current rate 8436480 is different from the runtime rate 48000
> [168905.185825] usb 3-2.1.2: current rate 30465 is different from the runtime rate 96000
> 
> As can be seen from the hexadecimal conversion, the current rate read
> back is byte-reversed from the rate that was set.
> 
> 44100 == 0x00ac44, 4500480 == 0x44ac00
> 48000 == 0x00bb80, 8436480 == 0x80bb00
> 96000 == 0x017700,   30465 == 0x007701
> 
> Rather than implementing a new quirk to reverse the order, just skip
> checking the rate to avoid spamming the log.
> 
> Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>

Thanks, applied now with Cc to stable.


Takashi