lkml.org 
[lkml]   [2006]   [Mar]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] 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.

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/
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");
\
 
 \ /
  Last update: 2006-03-03 17:12    [W:0.027 / U:0.048 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site