From mboxrd@z Thu Jan 1 00:00:00 1970 From: Len Brown Subject: [PATCH 14/19] ACPI: suspend: restore BM_RLD on resume Date: Sat, 16 May 2009 02:02:11 -0400 Message-ID: <815ab0fd40579ad2aa42058298073503648762b9.1242453625.git.len.brown@intel.com> References: <1242453736-20763-1-git-send-email-lenb@kernel.org> Return-path: Received: from vms173017pub.verizon.net ([206.46.173.17]:33333 "EHLO vms173017pub.verizon.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752977AbZEPGCb (ORCPT ); Sat, 16 May 2009 02:02:31 -0400 Received: from localhost.localdomain ([96.237.168.40]) by vms173017.mailsrvcs.net (Sun Java(tm) System Messaging Server 6.3-7.04 (built Sep 26 2008; 32bit)) with ESMTPA id <0KJQ00F163G2YURT@vms173017.mailsrvcs.net> for linux-acpi@vger.kernel.org; Sat, 16 May 2009 01:02:27 -0500 (CDT) In-reply-to: <1242453736-20763-1-git-send-email-lenb@kernel.org> In-reply-to: <45cb50e646d1560eff01c5ad0f0df3c7fd6148dd.1242453625.git.len.brown@intel.com> References: <45cb50e646d1560eff01c5ad0f0df3c7fd6148dd.1242453625.git.len.brown@intel.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: linux-acpi@vger.kernel.org Cc: Len Brown From: Len Brown In 2.6.29, 31878dd86b7df9a147f5e6cc6e07092b4308782b "ACPI: remove BM_RLD access from idle entry path" moved BM_RLD initialization to init-time from run time. But we discovered that some BIOS do not restore BM_RLD after suspend, causing device errors on C3 and C4 after resume. So now the kernel restores BM_RLD. http://bugzilla.kernel.org/show_bug.cgi?id=13032 Signed-off-by: Len Brown --- drivers/acpi/processor_idle.c | 23 +++++++++++++++++++++++ 1 files changed, 23 insertions(+), 0 deletions(-) diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index f7ca8c5..c1d59cf 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -202,15 +202,38 @@ static void acpi_state_timer_broadcast(struct acpi_processor *pr, * Suspend / resume control */ static int acpi_idle_suspend; +static u32 saved_bm_rld; + +static void acpi_idle_bm_rld_save(void) +{ + acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld); +} +static void acpi_idle_bm_rld_restore(void) +{ + u32 resumed_bm_rld; + + acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld); + + if (resumed_bm_rld != saved_bm_rld) + acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld); +} int acpi_processor_suspend(struct acpi_device * device, pm_message_t state) { + if (acpi_idle_suspend == 1) + return 0; + + acpi_idle_bm_rld_save(); acpi_idle_suspend = 1; return 0; } int acpi_processor_resume(struct acpi_device * device) { + if (acpi_idle_suspend == 0) + return 0; + + acpi_idle_bm_rld_restore(); acpi_idle_suspend = 0; return 0; } -- 1.6.0.6