Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751928AbdIMUwP (ORCPT ); Wed, 13 Sep 2017 16:52:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:49702 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751479AbdIMUtA (ORCPT ); Wed, 13 Sep 2017 16:49:00 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0CE8A20C48 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=atull@kernel.org From: Alan Tull To: Moritz Fischer Cc: Alan Tull , linux-kernel@vger.kernel.org, linux-fpga@vger.kernel.org Subject: [PATCH v4 08/18] fpga: region: fix slow warning with more than one overlay Date: Wed, 13 Sep 2017 15:48:31 -0500 Message-Id: <20170913204841.2730-9-atull@kernel.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170913204841.2730-1-atull@kernel.org> References: <20170913204841.2730-1-atull@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1487 Lines: 40 When DT overlays are applied, each FPGA region keeps track of the fpga image info as region->info. This pointer is assigned only if an overlay causes the FPGA to be programmed. As it stands, this pointer can be overwritten, causing a slow warning later when overlays are removed. This patch fixes this by changing the allowed behaviour. If a region has received an overlay that programmed the FPGA, reject other overlays that try to program the FPGA. To reprogram the FPGA, first remove the overlay. This makes sense as removing the overlay also removes the devices cleanly. Note that overlays that make DT changes without reprogramming the FPGA are exempt from this restriction. Signed-off-by: Alan Tull --- v2: split out from another patch v3: better explanation in header v4: no change to this patch in this version of patchset --- drivers/fpga/fpga-region.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c index afac543..35af952 100644 --- a/drivers/fpga/fpga-region.c +++ b/drivers/fpga/fpga-region.c @@ -355,6 +355,11 @@ static int fpga_region_notify_pre_apply(struct fpga_region *region, const char *firmware_name; int ret; + if (region->info) { + dev_err(dev, "Region already has overlay applied.\n"); + return -EINVAL; + } + /* * Reject overlay if child FPGA Regions added in the overlay have * firmware-name property (would mean that an FPGA region that has -- 2.7.4