From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Valdis Kl=?utf-8?Q?=c4=93?=tnieks" Subject: Re: [PATCHv5] drivers/amba: add reset control to amba bus probe Date: Tue, 27 Aug 2019 15:25:24 -0400 Message-ID: <30608.1566933924@turing-police> References: <20190826154252.22952-1-dinguyen@kernel.org> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1566933924_1612P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190826154252.22952-1-dinguyen@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Dinh Nguyen Cc: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, robh@kernel.org, linux@armlinux.org.uk, frowand.list@gmail.com, keescook@chromium.org, anton@enomsg.org, ccross@android.com, tony.luck@intel.com, daniel.thompson@linaro.org, linus.walleij@linaro.org, manivannan.sadhasivam@linaro.org, linux-arm-kernel@lists.infradead.org, p.zabel@pengutronix.de List-Id: devicetree@vger.kernel.org --==_Exmh_1566933924_1612P Content-Type: text/plain; charset=us-ascii On Mon, 26 Aug 2019 10:42:52 -0500, Dinh Nguyen said: > The primecell controller on some SoCs, i.e. SoCFPGA, is held in reset by > default. Until recently, the DMA controller was brought out of reset by the > bootloader(i.e. U-Boot). But a recent change in U-Boot, the peripherals > that are not used are held in reset and are left to Linux to bring them > out of reset. > > Add a mechanism for getting the reset property and de-assert the primecell > module from reset if found. This is a not a hard fail if the reset properti > is not present in the device tree node, so the driver will continue to > probe. Does this DTRT for both old and new U-Boots? My naive reading of this patch says on an old U-Boot, we end up attempting to bring it out of reset even though they had already been brought out. --==_Exmh_1566933924_1612P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Comment: Exmh version 2.9.0 11/07/2018 iQIVAwUBXWWDpAdmEQWDXROgAQIdrxAAon/T5pCtAGieFVjdAdhJjdPwqAhckoGF 6pdEvZoDtGgXHLPcNmX5YO0BXVRyCmQg8x57sEFISk2PrmS2Ax+UCVUpEaLQMjbD Dd0vJxZKe9Sz95p4ELvhEVvXPVq9+rkIEmWsVUVNGWN4sbpQc7vs2+JtHwFlx+2n m/taFbOH5qIRVYJQalBesf8WUcltYiA9ox4tKNYDSyKMqWVrGgvkxjO81appgJAZ 78x3eX94SyB2l7pJHNmRYdvr69kdFFzQDSbm1Y8rQnzar03fKUtpRmn1yXGc87wc SG08stZRhvr+H98MHe4LjkjYNxNO+k6R0q+jmdjMwD+NaDveKt43ydl+xF4kbYbl GzX+t51GUeU1PWnuHj+frYnUc0hv4N0xwC5SSWQ8vh0+0xQZsxYRluHLSEAw/VRp Qh8+wBX3rZ8Q8dQfoXPfj9z4DdWgXAlDoB1yAJDtdRG8sdcKfGL71bZjv7hB0Z6I XWnRsfqNevx/9Ev6shSve1jSHqGuuVb0ggOQVIcR9qaEeXI9UiRHOgK4qahEA6rI Im7p+uPlHE4agtwgvXy4QTXksuKqFj8xouyI9QQc5PtI60bT83/PXQzS7ywotkZh mFrpIGzD7D4xB4dQY4MB4jrGlPIArWfIKkqQ9jnTgD5dugR1CfejVwe7im0Lotyt 0bip0m4JQ/U= =XqAz -----END PGP SIGNATURE----- --==_Exmh_1566933924_1612P--