From mboxrd@z Thu Jan 1 00:00:00 1970 From: Enric Balletbo i Serra Subject: Re: [PATCH 4/4] platform/chrome: i2c: i2c-cros-ec-tunnel: Convert i2c tunnel to MFD Cell Date: Mon, 9 Dec 2019 15:41:33 +0100 Message-ID: <6f6b0ac7-37d8-e2a1-3249-223905c2a5b1@collabora.com> References: <20191121211053.48861-1-rrangel@chromium.org> <20191121140830.4.Iddc7dd74f893297cb932e9825d413e7890633b3d@changeid> <20191209131745.GM3468@dell> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20191209131745.GM3468@dell> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Lee Jones , Raul E Rangel Cc: Wolfram Sang , Akshu.Agrawal@amd.com, Guenter Roeck , Chanwoo Choi , linux-kernel@vger.kernel.org, Alexandre Belloni , linux-i2c@vger.kernel.org, Benson Leung List-Id: linux-i2c@vger.kernel.org Hi Lee, On 9/12/19 14:17, Lee Jones wrote: > On Thu, 21 Nov 2019, Raul E Rangel wrote: > >> If the i2c-cros-ec-tunnel driver is compiled into the kernel, it is >> possible that i2c-cros-ec-tunnel could be probed before cros_ec_XXX >> has finished initializing and setting the drvdata. This would cause a >> NULL pointer panic. >> >> Converting this driver over to an MFD solves the problem and aligns with >> where the cros_ec is going. >> >> Signed-off-by: Raul E Rangel >> --- >> You can now see the device node lives under the mfd device. >> >> $ find /sys/bus/platform/devices/cros-ec-dev.0.auto/cros-ec-i2c-tunnel.12.auto/ -iname firmware_node -exec ls -l '{}' \; >> /sys/bus/platform/devices/cros-ec-dev.0.auto/cros-ec-i2c-tunnel.12.auto/firmware_node -> ../../../../../../LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:1c/PNP0C09:00/GOOG0004:00/GOOG0012:00 >> /sys/bus/platform/devices/cros-ec-dev.0.auto/cros-ec-i2c-tunnel.12.auto/i2c-9/firmware_node -> ../../../../../../../LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:1c/PNP0C09:00/GOOG0004:00/GOOG0012:00 >> /sys/bus/platform/devices/cros-ec-dev.0.auto/cros-ec-i2c-tunnel.12.auto/i2c-9/i2c-10EC5682:00/firmware_node -> ../../../../../../../../LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:1c/PNP0C09:00/GOOG0004:00/GOOG0012:00/10EC5682:00 >> >> drivers/i2c/busses/i2c-cros-ec-tunnel.c | 36 +++++++++---------------- >> drivers/mfd/cros_ec_dev.c | 19 +++++++++++++ > > For my own reference: > Acked-for-MFD-by: Lee Jones > Note that there is a v2 for this patch and I did some comments [1] Thanks, Enric [1] https://patchwork.ozlabs.org/patch/1200560/