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* + viafb-reduce-i2c-timeout-and-delay.patch added to -mm tree
@ 2010-09-21 22:37 akpm
  0 siblings, 0 replies; only message in thread
From: akpm @ 2010-09-21 22:37 UTC (permalink / raw)
  To: mm-commits; +Cc: FlorianSchandinat, JosephChan, corbet


The patch titled
     viafb: reduce I2C timeout and delay
has been added to the -mm tree.  Its filename is
     viafb-reduce-i2c-timeout-and-delay.patch

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------------------------------------------------------
Subject: viafb: reduce I2C timeout and delay
From: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>

Reduce the value for I2C timeout and udelay.

The udelay was reduced to 10 (old: 40) which is still very high as for
standard-mode I2C even 5 should work.  This gives a speedup of factor 4
when talking to I2C devices.

The timeout was reduced to 2 (old: 20) which is taken from the radeon
driver so it should work as well.  This gives a speedup of factor 10 when
detecting that there is no I2C device we want to talk to.  This causes a
huge improvement of device initialization time.

Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Joseph Chan <JosephChan@via.com.tw>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/video/via/via_i2c.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff -puN drivers/video/via/via_i2c.c~viafb-reduce-i2c-timeout-and-delay drivers/video/via/via_i2c.c
--- a/drivers/video/via/via_i2c.c~viafb-reduce-i2c-timeout-and-delay
+++ a/drivers/video/via/via_i2c.c
@@ -202,8 +202,8 @@ static int create_i2c_bus(struct i2c_ada
 	algo->setscl = via_i2c_setscl;
 	algo->getsda = via_i2c_getsda;
 	algo->getscl = via_i2c_getscl;
-	algo->udelay = 40;
-	algo->timeout = 20;
+	algo->udelay = 10;
+	algo->timeout = 2;
 	algo->data = adap_cfg;
 
 	sprintf(adapter->name, "viafb i2c io_port idx 0x%02x",
_

Patches currently in -mm which might be from FlorianSchandinat@gmx.de are

linux-next.patch
viafb-add-interface-for-output-device-configuration.patch
viafb-limit-lcd-code-impact.patch
viafb-introduce-per-output-device-power-management.patch
viafb-vt1636-cleanup.patch
viafb-fix-i2c_transfer-error-handling.patch
viafb-enable-i2c-for-crt.patch
viafb-reduce-i2c-timeout-and-delay.patch
viafb-add-function-to-change-sync-polarity-per-device.patch
viafb-set-sync-polarity-for-all-output-devices.patch
viafb-add-a-mapping-of-supported-output-devices.patch
viafb-rename-output-devices.patch
viafb-add-documentation-for-proc-interface.patch


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