Changeset 5727

Timestamp:

05/20/09 09:21:19 (4 years ago)

Author:

khali

Message:

Backport from a Linux 2.6 patch from David Airlie:

i2c-algo-bit: Fix timeout test

When fetching DDC using i2c algo bit, we were often seeing timeouts
before getting valid EDID on a retry. The VESA spec states 2ms is the
DDC timeout, so when this translates into 1 jiffie and we are close
to the end of the time period, it could return with a timeout less than
2ms.

Change this code to use time_after instead of time_after_eq.

Location:

i2c/trunk

Files:

• CHANGES (modified) (1 diff)
• kernel/i2c-algo-bit.c (modified) (1 diff)

i2c/trunk/CHANGES

@@ -12 +12 @@
   doc/writing-clients: Cleanups (2.6 backport)
   i2c.h: Drop I2C_FUNC_SMBUS_*I2C_BLOCK_2 defines (2.6 backport)
+  i2c-algo-bit: Fix timeout test (2.6 backport)
   i2c-core: Drop Linux 2.4 incompatibility mode
             Fix misplaced parentheses (2.6 backport)

i2c/trunk/kernel/i2c-algo-bit.c

@@ -96 +96 @@
                  * while they are processing data internally. 
                  */
-                if (time_after_eq(jiffies, start+adap->timeout)) {
+                if (time_after(jiffies, start + adap->timeout))
                         return -ETIMEDOUT;
-                }
                 if (current->need_resched)
                         schedule();