lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Mon, 25 Oct 2021 14:40:39 +0300 From: Andy Shevchenko <andy.shevchenko@...il.com> To: Hans de Goede <hdegoede@...hat.com> Cc: "Rafael J . Wysocki" <rjw@...ysocki.net>, Mark Gross <markgross@...nel.org>, Andy Shevchenko <andy@...radead.org>, Wolfram Sang <wsa@...-dreams.de>, Mika Westerberg <mika.westerberg@...ux.intel.com>, Daniel Scally <djrscally@...il.com>, Laurent Pinchart <laurent.pinchart@...asonboard.com>, Mauro Carvalho Chehab <mchehab@...nel.org>, Liam Girdwood <lgirdwood@...il.com>, Mark Brown <broonie@...nel.org>, Michael Turquette <mturquette@...libre.com>, Stephen Boyd <sboyd@...nel.org>, Len Brown <lenb@...nel.org>, ACPI Devel Maling List <linux-acpi@...r.kernel.org>, Platform Driver <platform-driver-x86@...r.kernel.org>, Linux Kernel Mailing List <linux-kernel@...r.kernel.org>, linux-i2c <linux-i2c@...r.kernel.org>, Sakari Ailus <sakari.ailus@...ux.intel.com>, Kate Hsuan <hpa@...hat.com>, Linux Media Mailing List <linux-media@...r.kernel.org>, linux-clk <linux-clk@...r.kernel.org> Subject: Re: [PATCH v4 11/11] platform/x86: int3472: Deal with probe ordering issues On Mon, Oct 25, 2021 at 12:42 PM Hans de Goede <hdegoede@...hat.com> wrote: > > The clk and regulator frameworks expect clk/regulator consumer-devices > to have info about the consumed clks/regulators described in the device's > fw_node. > > To work around this info missing from the ACPI tables on devices where > the int3472 driver is used, the int3472 MFD-cell drivers attach info about > consumers to the clks/regulators when registering these. > > This causes problems with the probe ordering wrt drivers for consumers > of these clks/regulators. Since the lookups are only registered when the > provider-driver binds, trying to get these clks/regulators before then > results in a -ENOENT error for clks and a dummy regulator for regulators. > > All the sensor ACPI fw-nodes have a _DEP dependency on the INT3472 ACPI > fw-node, so to work around these probe ordering issues the ACPI core / > i2c-code does not instantiate the I2C-clients for any ACPI devices > which have a _DEP dependency on an INT3472 ACPI device until all > _DEP-s are met. > > This relies on acpi_dev_clear_dependencies() getting called by the driver > for the _DEP-s when they are ready, add a acpi_dev_clear_dependencies() > call to the discrete.c probe code. > > In the tps68470 case calling acpi_dev_clear_dependencies() is already done > by the acpi_gpiochip_add() call done by the driver for the GPIO MFD cell > (The GPIO cell is deliberately the last cell created to make sure the > clk + regulator cells are already instantiated when this happens). > > However for proper probe ordering, the clk/regulator cells must not just > be instantiated the must be fully ready (the clks + regulators must be > registered with their subsystems). > > Add MODULE_SOFTDEP dependencies for the clk and regulator drivers for > the instantiated MFD-cells so that these are loaded before us and so > that they bind immediately when the platform-devs are instantiated. Just a side note: MODULE_SOFTDEP() won't work in some (special?) cases when module tools are limited in functionality (e.g. busybox implementation as of today). -- With Best Regards, Andy Shevchenko
Powered by blists - more mailing lists