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memory: emif: Fix the lpmode timeout calculation

The driver tries to round up the specified timeout cycles to
the next power of 2 value. This should be done defore updating
timeout variable.
Correcting this here.

Reported-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Lokesh Vutla 12 years ago
parent
commit
0a5f19cf30
1 changed files with 7 additions and 3 deletions
  1. 7 3
      drivers/memory/emif.c

+ 7 - 3
drivers/memory/emif.c

@@ -728,13 +728,17 @@ static u32 get_pwr_mgmt_ctrl(u32 freq, struct emif_data *emif, u32 ip_rev)
 	/* Timeout based on DDR frequency */
 	timeout = freq >= freq_threshold ? timeout_perf : timeout_pwr;
 
-	/* The value to be set in register is "log2(timeout) - 3" */
+	/*
+	 * The value to be set in register is "log2(timeout) - 3"
+	 * if timeout < 16 load 0 in register
+	 * if timeout is not a power of 2, round to next highest power of 2
+	 */
 	if (timeout < 16) {
 		timeout = 0;
 	} else {
-		timeout = __fls(timeout) - 3;
 		if (timeout & (timeout - 1))
-			timeout++;
+			timeout <<= 1;
+		timeout = __fls(timeout) - 3;
 	}
 
 	switch (lpmode) {