Return-path: Received: from mail-pv0-f174.google.com ([74.125.83.174]:64603 "EHLO mail-pv0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757627Ab1EZQnS convert rfc822-to-8bit (ORCPT ); Thu, 26 May 2011 12:43:18 -0400 Received: by pvg12 with SMTP id 12so382960pvg.19 for ; Thu, 26 May 2011 09:43:17 -0700 (PDT) From: Daniel Halperin Content-Type: text/plain; charset=us-ascii Subject: [PATCH/RFC] ath9k: fix two more bugs in tx power Date: Thu, 26 May 2011 09:43:09 -0700 Message-Id: <24ECC725-EA49-48CA-8B9D-FDD71BD257A0@cs.washington.edu> (sfid-20110526_184321_218962_47D32D52) Cc: blaise@willowgarage.com, adrian@freebsd.org To: linux-wireless , stable@kernel.org Mime-Version: 1.0 (Apple Message framework v1084) Sender: linux-wireless-owner@vger.kernel.org List-ID: This is the same fix as commit 841051602e3fa18ea468fe5a177aa92b6eb44b56 Author: Matteo Croce Date: Fri Dec 3 02:25:08 2010 +0100 The ath9k driver subtracts 3 dBm to the txpower as with two radios the signal power is doubled. The resulting value is assigned in an u16 which overflows and makes the card work at full power. in two more places. I grepped the ath tree and didn't find any others. Cc: stable@kernel.org Signed-off-by: Daniel Halperin --- RFC: Blaise Gassend actually pointed these two bugs out on 12/7/2010 but no one fixed. There was some discussion about refactoring/improving this code, but it never seemed to get anywhere. See this thread: http://comments.gmane.org/gmane.linux.drivers.ath9k.devel/4601 --- drivers/net/wireless/ath/ath9k/ar9003_eeprom.c | 10 ++++++++-- drivers/net/wireless/ath/ath9k/eeprom_9287.c | 10 ++++++++-- 2 files changed, 16 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c index 729534c..934e419 100644 --- a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c +++ b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c @@ -4645,10 +4645,16 @@ static void ar9003_hw_set_power_per_rate_table(struct ath_hw *ah, case 1: break; case 2: - scaledPower -= REDUCE_SCALED_POWER_BY_TWO_CHAIN; + if (scaledPower > REDUCE_SCALED_POWER_BY_TWO_CHAIN) + scaledPower -= REDUCE_SCALED_POWER_BY_TWO_CHAIN; + else + scaledPower = 0; break; case 3: - scaledPower -= REDUCE_SCALED_POWER_BY_THREE_CHAIN; + if (scaledPower > REDUCE_SCALED_POWER_BY_THREE_CHAIN) + scaledPower -= REDUCE_SCALED_POWER_BY_THREE_CHAIN; + else + scaledPower = 0; break; } diff --git a/drivers/net/wireless/ath/ath9k/eeprom_9287.c b/drivers/net/wireless/ath/ath9k/eeprom_9287.c index 7856f0d..343fc9f 100644 --- a/drivers/net/wireless/ath/ath9k/eeprom_9287.c +++ b/drivers/net/wireless/ath/ath9k/eeprom_9287.c @@ -524,10 +524,16 @@ static void ath9k_hw_set_ar9287_power_per_rate_table(struct ath_hw *ah, case 1: break; case 2: - scaledPower -= REDUCE_SCALED_POWER_BY_TWO_CHAIN; + if (scaledPower > REDUCE_SCALED_POWER_BY_TWO_CHAIN) + scaledPower -= REDUCE_SCALED_POWER_BY_TWO_CHAIN; + else + scaledPower = 0; break; case 3: - scaledPower -= REDUCE_SCALED_POWER_BY_THREE_CHAIN; + if (scaledPower > REDUCE_SCALED_POWER_BY_THREE_CHAIN) + scaledPower -= REDUCE_SCALED_POWER_BY_THREE_CHAIN; + else + scaledPower = 0; break; } scaledPower = max((u16)0, scaledPower); -- 1.7.0.4