From: David Vrabel <dvrabel@arcom.com>
To: jayakumar.alsa@gmail.com
Cc: Linux Kernel <linux-kernel@vger.kernel.org>, alsa-devel@alsa-project.org
Subject: [PATCH] ALSA: CS5535: shorter delays when accessing AC'97 codec registers
Date: Fri, 03 Mar 2006 16:09:51 +0000 [thread overview]
Message-ID: <44086A4F.1040403@arcom.com> (raw)
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The 10 ms sleeps while waiting for AC'97 codec register reads/writes to
complete are excessive given the maxmium time is one AC'97 frame (~21 us).
With AC'97 codecs with integrated touchscreens (like the UCB1400) this
improves the interactive performance of the touchscreen.
David Vrabel
--
David Vrabel, Design Engineer
Arcom, Clifton Road Tel: +44 (0)1223 411200 ext. 3233
Cambridge CB1 7EA, UK Web: http://www.arcom.com/
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ALSA: CS5535: shorter delays when accessing AC'97 codec registers
The 10 ms sleeps while waiting for AC'97 codec register reads/writes to
complete are excessive given the maxmium time is one AC'97 frame (~21 us).
With AC'97 codecs with integrated touchscreens (like the UCB1400) this
improves the interactive performance of the touchscreen.
Signed-off-by: David Vrabel <dvrabel@arcom.com>
Index: linux-2.6-working/sound/pci/cs5535audio/cs5535audio.c
===================================================================
--- linux-2.6-working.orig/sound/pci/cs5535audio/cs5535audio.c 2006-03-02 16:12:52.000000000 +0000
+++ linux-2.6-working/sound/pci/cs5535audio/cs5535audio.c 2006-03-03 15:47:30.000000000 +0000
@@ -62,7 +62,7 @@
tmp = cs_readl(cs5535au, ACC_CODEC_CNTL);
if (!(tmp & CMD_NEW))
break;
- msleep(10);
+ udelay(1);
} while (--timeout);
if (!timeout)
snd_printk(KERN_ERR "Failure writing to cs5535 codec\n");
@@ -80,14 +80,14 @@
regdata |= CMD_NEW;
cs_writel(cs5535au, ACC_CODEC_CNTL, regdata);
- wait_till_cmd_acked(cs5535au, 500);
+ wait_till_cmd_acked(cs5535au, 50);
timeout = 50;
do {
val = cs_readl(cs5535au, ACC_CODEC_STATUS);
if ((val & STS_NEW) && reg == (val >> 24))
break;
- msleep(10);
+ udelay(1);
} while (--timeout);
if (!timeout)
snd_printk(KERN_ERR "Failure reading cs5535 codec\n");
next reply other threads:[~2006-03-03 16:10 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-03-03 16:09 David Vrabel [this message]
2006-03-03 18:02 ` [Alsa-devel] " Takashi Iwai
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