Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753053Ab3CPGRE (ORCPT ); Sat, 16 Mar 2013 02:17:04 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:38655 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752685Ab3CPGQ7 (ORCPT ); Sat, 16 Mar 2013 02:16:59 -0400 From: Lokesh Vutla To: CC: , , , , Subject: [PATCH V2 1/8] memory: emif: Fix the lpmode timeout calculation Date: Sat, 16 Mar 2013 11:46:41 +0530 Message-ID: <1363414608-7448-2-git-send-email-lokeshvutla@ti.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1363414608-7448-1-git-send-email-lokeshvutla@ti.com> References: <1363414608-7448-1-git-send-email-lokeshvutla@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1562 Lines: 49 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 Signed-off-by: Lokesh Vutla Acked-by: Santosh Shilimkar --- Changes since V1: Updated Changelog and $subject Added a comment describing timeout calculation. drivers/memory/emif.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/memory/emif.c b/drivers/memory/emif.c index df08736..508763c 100644 --- a/drivers/memory/emif.c +++ b/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) { -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/