Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751854AbaBTJWp (ORCPT ); Thu, 20 Feb 2014 04:22:45 -0500 Received: from mga03.intel.com ([143.182.124.21]:58325 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751075AbaBTJWl (ORCPT ); Thu, 20 Feb 2014 04:22:41 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,511,1389772800"; d="scan'208";a="342323983" From: Jiang Liu To: David Airlie , "Rafael J. Wysocki" , Jiang Liu , Dave Airlie , Emil Velikov Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH] nouveau, ACPI: fix regression caused by b072e53 Date: Thu, 20 Feb 2014 17:23:16 +0800 Message-Id: <1392888200-27567-1-git-send-email-jiang.liu@linux.intel.com> X-Mailer: git-send-email 1.7.10.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Fix regression caused by commit b072e53, which breaks loading nouveau driver on optimus laptops. On some platforms, ACPI _DSM method (nouveau_op_dsm_muid, function 0) has special requirements on the fourth parameter, which is different from ACPI specifications. So revert to the private implementation to check availability of _DSM functions instead of using common acpi_check_dsm() interface. Reported-and-Tested-by: Maarten Lankhorst Signed-off-by: Jiang Liu --- drivers/gpu/drm/nouveau/nouveau_acpi.c | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nouveau_acpi.c b/drivers/gpu/drm/nouveau/nouveau_acpi.c index 4ef83df..83face3 100644 --- a/drivers/gpu/drm/nouveau/nouveau_acpi.c +++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c @@ -106,6 +106,29 @@ static int nouveau_optimus_dsm(acpi_handle handle, int func, int arg, uint32_t * return 0; } +/* + * On some platforms, _DSM(nouveau_op_dsm_muid, func0) has special + * requirements on the fourth parameter, so a private implementation + * instead of using acpi_check_dsm(). + */ +static int nouveau_check_optimus_dsm(acpi_handle handle) +{ + int result; + + /* + * Function 0 returns a Buffer containing available functions. + * The args parameter is ignored for function 0, so just put 0 in it + */ + if (nouveau_optimus_dsm(handle, 0, 0, &result)) + return 0; + + /* + * ACPI Spec v4 9.14.1: if bit 0 is zero, no function is supported. + * If the n-th bit is enabled, function n is supported + */ + return result & 1 && result & (1 << NOUVEAU_DSM_OPTIMUS_CAPS); +} + static int nouveau_dsm(acpi_handle handle, int func, int arg) { int ret = 0; @@ -207,8 +230,7 @@ static int nouveau_dsm_pci_probe(struct pci_dev *pdev) 1 << NOUVEAU_DSM_POWER)) retval |= NOUVEAU_DSM_HAS_MUX; - if (acpi_check_dsm(dhandle, nouveau_op_dsm_muid, 0x00000100, - 1 << NOUVEAU_DSM_OPTIMUS_CAPS)) + if (nouveau_check_optimus_dsm(dhandle)) retval |= NOUVEAU_DSM_HAS_OPT; if (retval & NOUVEAU_DSM_HAS_OPT) { -- 1.7.10.4 -- 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/