Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751416AbaLOOsM (ORCPT ); Mon, 15 Dec 2014 09:48:12 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:38712 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752842AbaLOO2b (ORCPT ); Mon, 15 Dec 2014 09:28:31 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Benjamin Herrenschmidt , Luis Henriques Subject: [PATCH 3.16.y-ckt 103/168] gpu/radeon: Set flag to indicate broken 64-bit MSI Date: Mon, 15 Dec 2014 14:25:57 +0000 Message-Id: <1418653622-21105-104-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.3 In-Reply-To: <1418653622-21105-1-git-send-email-luis.henriques@canonical.com> References: <1418653622-21105-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.7-ckt3 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Benjamin Herrenschmidt commit 91ed6fd2c383bb8f02d66e98b4a4d2f7207249dc upstream. Some radeon ASICs don't support all 64 address bits of MSIs despite advertising support for 64-bit MSIs in their configuration space. This breaks on systems such as IBM POWER7/8, where 64-bit MSIs can be assigned with some of the high address bits set. This makes use of the newly introduced "no_64bit_msi" flag in structure pci_dev to allow the MSI allocation code to fallback to 32-bit MSIs on those adapters. Signed-off-by: Benjamin Herrenschmidt Reviewed-by: Alex Deucher Signed-off-by: Luis Henriques --- drivers/gpu/drm/radeon/radeon_irq_kms.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/gpu/drm/radeon/radeon_irq_kms.c b/drivers/gpu/drm/radeon/radeon_irq_kms.c index 16807afab362..c74f12d125f7 100644 --- a/drivers/gpu/drm/radeon/radeon_irq_kms.c +++ b/drivers/gpu/drm/radeon/radeon_irq_kms.c @@ -202,6 +202,16 @@ static bool radeon_msi_ok(struct radeon_device *rdev) if (rdev->flags & RADEON_IS_AGP) return false; + /* + * Older chips have a HW limitation, they can only generate 40 bits + * of address for "64-bit" MSIs which breaks on some platforms, notably + * IBM POWER servers, so we limit them + */ + if (rdev->family < CHIP_BONAIRE) { + dev_info(rdev->dev, "radeon: MSI limited to 32-bit\n"); + rdev->pdev->no_64bit_msi = 1; + } + /* force MSI on */ if (radeon_msi == 1) return true; -- 2.1.3 -- 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/