From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: [PATCH v4 2/5] of: Use memory-controllers property for DMA parent Date: Thu, 13 Feb 2020 17:39:56 +0100 Message-ID: <20200213163959.819733-3-thierry.reding@gmail.com> References: <20200213163959.819733-1-thierry.reding@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20200213163959.819733-1-thierry.reding@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Arnd Bergmann , Will Deacon , Robin Murphy , Rob Herring Cc: Joerg Roedel , Olof Johansson , linux-tegra@vger.kernel.org, iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org List-Id: linux-tegra@vger.kernel.org From: Thierry Reding Prefer the memory-controllers property to determine the DMA parent of a device over the interconnects property, which can be ambiguous since it can be used to describe multiple paths to system memory. Signed-off-by: Thierry Reding --- drivers/of/address.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/drivers/of/address.c b/drivers/of/address.c index e8a39c3ec4d4..ae841bd36bb0 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c @@ -697,17 +697,24 @@ static struct device_node *__of_get_dma_parent(const struct device_node *np) struct of_phandle_args args; int ret, index; - index = of_property_match_string(np, "interconnect-names", "dma-mem"); - if (index < 0) - return of_get_parent(np); + ret = of_parse_phandle_with_args(np, "memory-controllers", + "#memory-controller-cells", + 0, &args); + if (!ret) { + return of_node_get(args.np); + } - ret = of_parse_phandle_with_args(np, "interconnects", - "#interconnect-cells", - index, &args); - if (ret < 0) - return of_get_parent(np); + index = of_property_match_string(np, "interconnect-names", "dma-mem"); + if (index >= 0) { + ret = of_parse_phandle_with_args(np, "interconnects", + "#interconnect-cells", + index, &args); + if (!ret) { + return of_node_get(args.np); + } + } - return of_node_get(args.np); + return of_get_parent(np); } static struct device_node *of_get_next_dma_parent(struct device_node *np) -- 2.24.1