From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ED62FC432C0 for ; Mon, 25 Nov 2019 16:51:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C198D2068E for ; Mon, 25 Nov 2019 16:51:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728958AbfKYQvY (ORCPT ); Mon, 25 Nov 2019 11:51:24 -0500 Received: from bhuna.collabora.co.uk ([46.235.227.227]:60890 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728683AbfKYQvY (ORCPT ); Mon, 25 Nov 2019 11:51:24 -0500 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: eballetbo) with ESMTPSA id AEA5A28FCBE Subject: Re: [PATCH 4/4] platform/chrome: i2c: i2c-cros-ec-tunnel: Convert i2c tunnel to MFD Cell To: Raul E Rangel , Wolfram Sang Cc: Akshu.Agrawal@amd.com, Guenter Roeck , Chanwoo Choi , linux-kernel@vger.kernel.org, Alexandre Belloni , linux-i2c@vger.kernel.org, Lee Jones , Benson Leung References: <20191121211053.48861-1-rrangel@chromium.org> <20191121140830.4.Iddc7dd74f893297cb932e9825d413e7890633b3d@changeid> From: Enric Balletbo i Serra Message-ID: Date: Mon, 25 Nov 2019 17:51:19 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <20191121140830.4.Iddc7dd74f893297cb932e9825d413e7890633b3d@changeid> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Raul, On 21/11/19 22:10, 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 +++++++++++++ > 2 files changed, 32 insertions(+), 23 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-cros-ec-tunnel.c b/drivers/i2c/busses/i2c-cros-ec-tunnel.c > index 5d91e33eb600..2e3217678fa3 100644 > --- a/drivers/i2c/busses/i2c-cros-ec-tunnel.c > +++ b/drivers/i2c/busses/i2c-cros-ec-tunnel.c > @@ -6,6 +6,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -27,7 +28,6 @@ > struct ec_i2c_device { > struct device *dev; > struct i2c_adapter adap; > - struct cros_ec_device *ec; > > u16 remote_bus; > > @@ -176,6 +176,7 @@ static int ec_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg i2c_msgs[], > { > struct ec_i2c_device *bus = adap->algo_data; > struct device *dev = bus->dev; > + struct cros_ec_dev *ec = dev_get_drvdata(dev->parent); > const u16 bus_num = bus->remote_bus; > int request_len; > int response_len; > @@ -183,6 +184,16 @@ static int ec_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg i2c_msgs[], > int result; > struct cros_ec_command *msg; > > + if (!ec) { > + dev_err(dev, "%s: ec is missing!\n", __func__); > + return -EINVAL; > + } > + > + if (!ec->ec_dev) { > + dev_err(dev, "%s: ec->ec_dev is missing!\n", __func__); > + return -EINVAL; > + } > + Are those checks needed? Is that possible? > request_len = ec_i2c_count_message(i2c_msgs, num); > if (request_len < 0) { > dev_warn(dev, "Error constructing message %d\n", request_len); > @@ -212,7 +223,7 @@ static int ec_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg i2c_msgs[], > msg->outsize = request_len; > msg->insize = response_len; > > - result = cros_ec_cmd_xfer_status(bus->ec, msg); > + result = cros_ec_cmd_xfer_status(ec->ec_dev, msg); > if (result < 0) { > dev_err(dev, "Error transferring EC i2c message %d\n", result); > goto exit; > @@ -241,17 +252,11 @@ static const struct i2c_algorithm ec_i2c_algorithm = { > > static int ec_i2c_probe(struct platform_device *pdev) > { > - struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent); > struct device *dev = &pdev->dev; > struct ec_i2c_device *bus = NULL; > u32 remote_bus; > int err; > > - if (!ec->cmd_xfer) { > - dev_err(dev, "Missing sendrecv\n"); > - return -EINVAL; > - } > - > bus = devm_kzalloc(dev, sizeof(*bus), GFP_KERNEL); > if (bus == NULL) > return -ENOMEM; > @@ -263,7 +268,6 @@ static int ec_i2c_probe(struct platform_device *pdev) > } > bus->remote_bus = remote_bus; > > - bus->ec = ec; > bus->dev = dev; > > bus->adap.owner = THIS_MODULE; > @@ -292,25 +296,11 @@ static int ec_i2c_remove(struct platform_device *dev) > return 0; > } > > -static const struct of_device_id cros_ec_i2c_of_match[] = { > - { .compatible = "google,cros-ec-i2c-tunnel" }, > - {}, > -}; > -MODULE_DEVICE_TABLE(of, cros_ec_i2c_of_match); > - > -static const struct acpi_device_id cros_ec_i2c_tunnel_acpi_id[] = { > - { "GOOG0012", 0 }, So, you're removing something that you just added in a previous patch. So is really the change in the previous patch needed? > - { } > -}; > -MODULE_DEVICE_TABLE(acpi, cros_ec_i2c_tunnel_acpi_id); > - > static struct platform_driver ec_i2c_tunnel_driver = { > .probe = ec_i2c_probe, > .remove = ec_i2c_remove, > .driver = { > .name = "cros-ec-i2c-tunnel", > - .acpi_match_table = ACPI_PTR(cros_ec_i2c_tunnel_acpi_id), > - .of_match_table = of_match_ptr(cros_ec_i2c_of_match), I don't understand this change, why? The id should be in the driver to match. > }, > }; > > diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c > index 1efdba18f20b..61b20e061f75 100644 > --- a/drivers/mfd/cros_ec_dev.c > +++ b/drivers/mfd/cros_ec_dev.c > @@ -113,6 +113,18 @@ static const struct mfd_cell cros_ec_vbc_cells[] = { > { .name = "cros-ec-vbc", } > }; > > +static struct mfd_cell_acpi_match cros_ec_i2c_tunnel_acpi_match = { > + .pnpid = "GOOG0012" > +}; > + > +static struct mfd_cell cros_ec_fw_cells[] = { > + { > + .name = "cros-ec-i2c-tunnel", > + .acpi_match = &cros_ec_i2c_tunnel_acpi_match, > + .of_compatible = "google,cros-ec-i2c-tunnel" Ah, I see. The acpi_match and the of_compatible should be in the i2c-cros-ec-tunnel driver not here. Why you changed? Didn't work? > + }, > +}; > + > int cros_ec_check_features(struct cros_ec_dev *ec, int feature) > { > struct cros_ec_command *msg; > @@ -485,6 +497,13 @@ static int ec_device_probe(struct platform_device *pdev) > "failed to add cros-ec platform devices: %d\n", > retval); > > + retval = mfd_add_hotplug_devices(ec->dev, cros_ec_fw_cells, > + ARRAY_SIZE(cros_ec_fw_cells)); > + if (retval) > + dev_warn(ec->dev, > + "failed to add cros-ec fw platform devices: %d\n", > + retval); > + I think this should go inside the cros_ec_platform_cells, so drop this and add the "cros-ec-i2c-tunnel" in the cros_ec_platform_cells[] table is enough. Thanks, Enric > /* Check whether this EC instance has a VBC NVRAM */ > node = ec->ec_dev->dev->of_node; > if (of_property_read_bool(node, "google,has-vbc-nvram")) { >