From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263913AbUCZDdd (ORCPT ); Thu, 25 Mar 2004 22:33:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263667AbUCZDdc (ORCPT ); Thu, 25 Mar 2004 22:33:32 -0500 Received: from gate.crashing.org ([63.228.1.57]:61576 "EHLO gate.crashing.org") by vger.kernel.org with ESMTP id S263913AbUCZDb0 (ORCPT ); Thu, 25 Mar 2004 22:31:26 -0500 Subject: [PATCH] powerbook via-pmu races From: Benjamin Herrenschmidt To: Andrew Morton Cc: Linus Torvalds , Linux Kernel list Content-Type: text/plain Message-Id: <1080271749.1196.19.camel@gaston> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.5 Date: Fri, 26 Mar 2004 14:29:09 +1100 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi ! This patch fixes some racy code in the management of asynchronous brightness and battery requests in the via-pmu driver used on powerbooks. This should fix some preempt related problems (there is no SMP powerbook yet :) Ben. diff -urN linux-2.5/drivers/macintosh/via-pmu.c linuxppc-2.5-benh/drivers/macintosh/via-pmu.c --- linux-2.5/drivers/macintosh/via-pmu.c 2004-03-01 18:11:44.000000000 +1100 +++ linuxppc-2.5-benh/drivers/macintosh/via-pmu.c 2004-03-25 18:52:00.000000000 +1100 @@ -137,7 +137,8 @@ static int data_len; static volatile int adb_int_pending; static volatile int disable_poll; -static struct adb_request bright_req_1, bright_req_2, bright_req_3; +static struct adb_request bright_req_1, bright_req_2; +static unsigned long async_req_locks; static struct device_node *vias; static int pmu_kind = PMU_UNKNOWN; static int pmu_fully_inited = 0; @@ -404,7 +405,6 @@ bright_req_1.complete = 1; bright_req_2.complete = 1; - bright_req_3.complete = 1; #ifdef CONFIG_PMAC_PBOOK batt_req.complete = 1; if (pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,0,-1) >= 0) @@ -710,6 +710,8 @@ pmu_batteries[pmu_cur_battery].amperage = amperage; pmu_batteries[pmu_cur_battery].voltage = voltage; pmu_batteries[pmu_cur_battery].time_remaining = time; + + clear_bit(0, &async_req_locks); } static void __pmac @@ -785,12 +787,14 @@ pmu_batteries[pmu_cur_battery].time_remaining = 0; pmu_cur_battery = (pmu_cur_battery + 1) % pmu_battery_count; + + clear_bit(0, &async_req_locks); } static void __pmac query_battery_state(void) { - if (!batt_req.complete) + if (test_and_set_bit(0, &async_req_locks)) return; if (pmu_kind == PMU_OHARE_BASED) pmu_request(&batt_req, done_battery_state_ohare, @@ -1690,20 +1694,30 @@ return 0; } +static void __openfirmware +pmu_bright_complete(struct adb_request *req) +{ + if (req == &bright_req_1) + clear_bit(1, &async_req_locks); + if (req == &bright_req_2) + clear_bit(2, &async_req_locks); +} + static int __openfirmware pmu_set_backlight_level(int level, void* data) { if (vias == NULL) return -ENODEV; - if (!bright_req_1.complete) + if (test_and_set_bit(1, &async_req_locks)) return -EAGAIN; - pmu_request(&bright_req_1, NULL, 2, PMU_BACKLIGHT_BRIGHT, + pmu_request(&bright_req_1, pmu_bright_complete, 2, PMU_BACKLIGHT_BRIGHT, backlight_to_bright[level]); - if (!bright_req_2.complete) + if (test_and_set_bit(2, &async_req_locks)) return -EAGAIN; - pmu_request(&bright_req_2, NULL, 2, PMU_POWER_CTRL, PMU_POW_BACKLIGHT - | (level > BACKLIGHT_OFF ? PMU_POW_ON : PMU_POW_OFF)); + pmu_request(&bright_req_2, pmu_bright_complete, 2, PMU_POWER_CTRL, + PMU_POW_BACKLIGHT | (level > BACKLIGHT_OFF ? + PMU_POW_ON : PMU_POW_OFF)); return 0; } @@ -2330,6 +2344,8 @@ return -EBUSY; } + preempt_disable(); + /* Make sure the decrementer won't interrupt us */ asm volatile("mtdec %0" : : "r" (0x7fffffff)); /* Make sure any pending DEC interrupt occurring while we did @@ -2352,6 +2368,7 @@ if (ret) { wakeup_decrementer(); local_irq_enable(); + preempt_enable(); device_resume(); broadcast_wake(); printk(KERN_ERR "Driver powerdown failed\n"); @@ -2360,7 +2377,8 @@ /* Wait for completion of async backlight requests */ while (!bright_req_1.complete || !bright_req_2.complete || - !bright_req_3.complete || !batt_req.complete) + + !batt_req.complete) pmu_poll(); /* Giveup the lazy FPU & vec so we don't have to back them @@ -2398,6 +2416,8 @@ pmu_blink(1); + preempt_enable(); + /* Resume devices */ device_resume(); @@ -2673,9 +2693,9 @@ mb(); pmac_wakeup_devices(); - pbook_free_pci_save(); iounmap(mem_ctrl); + return 0; }