From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [PATCH V7 1/2] arm64: dtsi: Fix SDMMC address range Date: Thu, 10 Jan 2019 15:47:31 +0100 Message-ID: <20190110144731.GA25353@ulmo> References: <1546457808-18270-1-git-send-email-skomatineni@nvidia.com> <1546457808-18270-2-git-send-email-skomatineni@nvidia.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="7AUc2qLy4jB3hD7Z" Return-path: Content-Disposition: inline In-Reply-To: <1546457808-18270-2-git-send-email-skomatineni@nvidia.com> Sender: linux-kernel-owner@vger.kernel.org To: Sowjanya Komatineni Cc: adrian.hunter@intel.com, ulf.hansson@linaro.org, jonathanh@nvidia.com, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org List-Id: linux-tegra@vger.kernel.org --7AUc2qLy4jB3hD7Z Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Jan 02, 2019 at 11:36:47AM -0800, Sowjanya Komatineni wrote: > This patch fixes the SDMMC Controllers address space to be exact > defined register address range as per the design. >=20 > SDMMC Controller supporting Command Queue has CQHCI registers at > offset 0xF000. >=20 > This fix helps to identify the Tegra SDMMC Controllers supporting > Command Queue based on the size of address space. >=20 > Signed-off-by: Sowjanya Komatineni > --- > arch/arm64/boot/dts/nvidia/tegra186.dtsi | 6 +++--- > arch/arm64/boot/dts/nvidia/tegra194.dtsi | 4 ++-- > 2 files changed, 5 insertions(+), 5 deletions(-) After applying these patches I'm having second thoughts about the DT aspect of this. I know you and Timo had originally argued to advertise the capability via an extra property in DT instead of updating the reg property. In retrospect, I think that's the right thing to do, after all. The problem I'm running into is that if I apply patch 2/2 without the first patch, then both Jetson TX2 and Jetson AGX Xavier crash on boot because they try to access these registers (the I/O memory size is 0x10000 for all controllers). So we're effectively breaking ABI with existing device trees. I don't know of a way to work around that other than the separate property. Would you mind changing the series to contain: 1) a patch updating the device tree bindings with the new optional property that would mark SDMMC4 as CQE capable (make sure to Cc devicetree@vger.kernel.org on that patch) 2) replace this patch by one which only adds the new "supports-cqe" property 3) update the second patch to make the decision based on the flag rather than the I/O memory size Sorry for the back and forth on this. I evidently hadn't thought this through. Thierry --7AUc2qLy4jB3hD7Z Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEiOrDCAFJzPfAjcif3SOs138+s6EFAlw3WwAACgkQ3SOs138+ s6Er5hAAjcqLKJlSzT0ipK8NA2g937YzOBD4HRe/jMLXTbDcpjYTzndQVNGCttsY Zjw4SPTxjZRBEOZsb3DKmYWCbriqVJpi3Ym2JiG6afv/BVw0UlYmOhp9uBOlzp+Z MSXtkkwA5QKMUT+BYwhnTR50SzA0EBD/LCrCJKRX9Gr7d7XrZjgaGVMo/yIp9isj xYVZbg3+iKdf+U3bEQOYKWw53mg8+Zb91voWX/M+yEfRwjTPOH4Wu4B8geHQxCgo TX6uMZrJQvJX0N3puGaxZp/SzE8qficNnJXXPRSXQjXqRm5P73BN3D/1GZxJUlcb sIx0hte4/B9R/9N9OvpSsQAYPZzTXwG1khOcpU3lIzfozsttDCOvWoJCSXegaWFv BaKcwYj76luUxtiP39Fboe/aYROA+c1m5wl7uMz2/Gh921LbAuVCundN5f7VzH7g fiHcDX5DRtIF9qBHA5pXOueM6DXZS2Fh2StJBoqcVv9efFF5bogOoP/GgCJmjk7Z fvZu/KJkqitcNUAg3HuQ+JndDSz3s79ddU5zN7E7EAcHQxXX2HICPx5fhK4RDXei WK8WMU5kZmCN6xHBtAKYJgdZhjv3ySc1XNnJTSzcrcfZdE8KrwwNorMCALNfy3hU bam38+6lFyHNxrnSG+7CF0ySc6nZ07P/8XCFl+ZIP+YGDiD0ILQ= =JW8s -----END PGP SIGNATURE----- --7AUc2qLy4jB3hD7Z--