All of lore.kernel.org
 help / color / mirror / Atom feed
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Hans de Goede <hdegoede@redhat.com>,
	Dan Scally <djrscally@gmail.com>,
	linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org,
	linux-gpio@vger.kernel.org, linux-i2c@vger.kernel.org,
	linux-media@vger.kernel.org, devel@acpica.org, rjw@rjwysocki.net,
	lenb@kernel.org, gregkh@linuxfoundation.org,
	mika.westerberg@linux.intel.com, linus.walleij@linaro.org,
	bgolaszewski@baylibre.com, wsa@kernel.org, yong.zhi@intel.com,
	sakari.ailus@linux.intel.com, bingbu.cao@intel.com,
	tian.shu.qiu@intel.com, mchehab@kernel.org,
	robert.moore@intel.com, erik.kaneda@intel.com, pmladek@suse.com,
	rostedt@goodmis.org, sergey.senozhatsky@gmail.com,
	linux@rasmusvillemoes.dk,
	kieran.bingham+renesas@ideasonboard.com,
	jacopo+renesas@jmondi.org,
	laurent.pinchart+renesas@ideasonboard.com,
	jorhand@linux.microsoft.com, kitakar@gmail.com,
	heikki.krogerus@linux.intel.com
Subject: Re: [PATCH 18/18] ipu3: Add driver for dummy INT3472 ACPI device
Date: Wed, 2 Dec 2020 17:15:07 +0200	[thread overview]
Message-ID: <20201202151507.GH4077@smile.fi.intel.com> (raw)
In-Reply-To: <20201202124847.GG4486@pendragon.ideasonboard.com>

On Wed, Dec 02, 2020 at 02:48:47PM +0200, Laurent Pinchart wrote:
> On Tue, Dec 01, 2020 at 09:34:58PM +0100, Hans de Goede wrote:
> > On 12/1/20 8:21 PM, Andy Shevchenko wrote:
> > > On Tue, Dec 01, 2020 at 09:06:38PM +0200, Laurent Pinchart wrote:

...

> > > I would rather ask Hans' opinion since he has quite an expertise with DMI for
> > > good and bad.
> > 
> > So generally there are 2 ways how things like this can go:
> > 
> > 1) There is sufficient information in the ACPI table and we use data from the
> > ACPI tables
> > 
> > 2) There is unsufficient info in the ACPI tables (or we don't know how to
> > get / interpret the data) and we use DMI quirks
> 
> And this specific case I believe there is sufficient data in the ACPI
> tables, as I don't believe the Windows driver uses DMI quirks, or comes
> in the form of machine-specific binaries. We however don't know how to
> interpret all the data, but that should hopefully get better over time
> (especially as we'll get more data points, with ACPI dumps from machines
> whose schematics have leaked).

I think you are too optimistic about this part of Windows drivers.
I would rather think about hardware stuck with the same frequencies which
simply are hard coded in the Windows driver.

I have description of ASL for this camera, but I don't see anything like this
you are describing.

> > Although we do often also use a combination, getting what we can from ACPI,
> > combined with a set of defaults for what we cannot get from ACPI
> > based on what reference designs use (IOW what most devices seem to have
> > copy and pasted). Combined with DMI quirks for when the defaults do not
> > work (which is quite often).
> > 
> > Depending on if "not working because of wrong defaults" has bad side effects,
> > another option is also to only allow the driver to load on devices which
> > have the necessary info provided through a DMI match.
> 
> Right now there shouldn't be bad side effects, but in the future we'll
> need to setup a PMIC whose output voltages can be controlled, and
> getting it wrong would be very bad. For that I'll definitely vote for
> DMI match to start with, but I don't think that precludes using data
> from ACPI. We could just prevent the driver from loading if the machine
> isn't whitelisted in DMI matches, and still use ACPI data.

I also think about DMI as a narrowing scope of supported platforms.

-- 
With Best Regards,
Andy Shevchenko



  reply	other threads:[~2020-12-02 15:16 UTC|newest]

Thread overview: 159+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-30 13:31 [PATCH 00/18] Add functionality to ipu3-cio2 driver allowing software_node connections to sensors on platforms designed for Windows Daniel Scally
2020-11-30 13:31 ` [PATCH 01/18] property: Return true in fwnode_device_is_available for node types that do not implement this operation Daniel Scally
2020-11-30 16:05   ` Laurent Pinchart
2020-11-30 17:21   ` Andy Shevchenko
2020-12-01  3:12   ` Bingbu Cao
2020-12-01  8:46     ` Dan Scally
2020-11-30 13:31 ` [PATCH 02/18] property: Add support for calling fwnode_graph_get_endpoint_by_id() for fwnode->secondary Daniel Scally
2020-11-30 16:08   ` Laurent Pinchart
2020-11-30 17:29   ` Andy Shevchenko
2020-11-30 17:28     ` Laurent Pinchart
2020-11-30 17:53       ` Andy Shevchenko
2020-11-30 18:41         ` Laurent Pinchart
2020-11-30 19:21           ` Andy Shevchenko
2020-12-02 10:13     ` Dan Scally
2020-11-30 13:31 ` [PATCH 03/18] software_node: Fix failure to put() and get() references to children in software_node_get_next_child() Daniel Scally
2020-11-30 16:10   ` Laurent Pinchart
2020-11-30 17:30   ` Andy Shevchenko
2020-11-30 13:31 ` [PATCH 04/18] software_node: Enforce parent before child ordering of nodes array for software_node_register_nodes() Daniel Scally
2020-11-30 16:11   ` Laurent Pinchart
2020-11-30 16:12     ` Laurent Pinchart
2020-11-30 23:10       ` Dan Scally
2020-11-30 17:35   ` Andy Shevchenko
2020-11-30 17:37     ` Andy Shevchenko
2020-11-30 13:31 ` [PATCH 05/18] software_node: Alter software_node_unregister_nodes() to unregister the array in reverse order Daniel Scally
2020-11-30 16:14   ` Laurent Pinchart
2020-11-30 17:45   ` Andy Shevchenko
2020-12-01 23:36     ` Dan Scally
2020-11-30 13:31 ` [PATCH 06/18] software_node: amend software_node_unregister_node_group() to perform unregistration of array in reverse order to be consistent with software_node_unregister_nodes() Daniel Scally
2020-11-30 16:17   ` Laurent Pinchart
2020-11-30 17:47     ` Andy Shevchenko
2020-12-02 10:04       ` Dan Scally
2020-12-01 18:18   ` Dan Carpenter
2020-12-01 18:18     ` Dan Carpenter
2020-12-01 18:18     ` Dan Carpenter
2020-11-30 13:31 ` [PATCH 07/18] software_node: Add support for fwnode_graph*() family of functions Daniel Scally
2020-11-30 16:25   ` Laurent Pinchart
2020-11-30 23:34     ` Dan Scally
2020-11-30 13:31 ` [PATCH 08/18] lib/test_printf.c: Use helper function to unwind array of software_nodes Daniel Scally
2020-11-30 15:54   ` Sergey Senozhatsky
2020-11-30 16:26   ` Laurent Pinchart
2020-11-30 13:31 ` [PATCH 09/18] ipu3-cio2: Add T: entry to MAINTAINERS Daniel Scally
2020-11-30 13:31 ` [PATCH 10/18] ipu3-cio2: Rename ipu3-cio2.c to allow module to be built from multiple source files retaining ipu3-cio2 name Daniel Scally
2020-12-01  6:56   ` Bingbu Cao
2020-12-01  7:07     ` Bingbu Cao
2020-11-30 13:31 ` [PATCH 11/18] media: v4l2-core: v4l2-async: Check possible match in match_fwnode based on sd->fwnode->secondary Daniel Scally
2020-11-30 16:27   ` Laurent Pinchart
2020-11-30 17:55   ` Andy Shevchenko
2020-11-30 13:31 ` [PATCH 12/18] acpi: Add acpi_dev_get_next_match_dev() and macro to iterate through acpi_devices matching a given _HID Daniel Scally
2020-11-30 17:58   ` Andy Shevchenko
2020-11-30 13:31 ` [PATCH 13/18] ipu3-cio2: Add functionality allowing software_node connections to sensors on platforms designed for Windows Daniel Scally
2020-11-30 17:09   ` Laurent Pinchart
2020-11-30 18:14     ` Andy Shevchenko
2020-12-01 22:08     ` Dan Scally
2020-12-01 22:11       ` Dan Scally
2020-12-01 22:30       ` Laurent Pinchart
2020-12-01 23:15         ` Dan Scally
2020-12-02 10:38         ` Sakari Ailus
2020-12-02 10:53           ` Dan Scally
2020-12-02 12:02             ` Andy Shevchenko
2020-12-02 22:44               ` Dan Scally
2020-12-02 12:01           ` Andy Shevchenko
2020-11-30 20:35   ` Sakari Ailus
2020-12-01  8:13     ` Dan Scally
2020-12-01 15:06     ` Andy Shevchenko
2020-12-15 10:28     ` Daniel Scally
2020-12-15 10:32       ` Daniel Scally
2020-12-15 22:02       ` Sakari Ailus
2020-12-17 14:17         ` Daniel Scally
2020-11-30 13:31 ` [PATCH 14/18] acpi: utils: Add function to fetch dependent acpi_devices Daniel Scally
2020-11-30 18:23   ` Andy Shevchenko
2020-11-30 18:40     ` Laurent Pinchart
2020-11-30 23:54     ` Dan Scally
2020-12-01 15:10       ` Andy Shevchenko
2020-12-01 15:23         ` Dan Scally
2020-11-30 13:31 ` [PATCH 15/18] i2c: i2c-core-acpi: Add i2c_acpi_dev_name() Daniel Scally
2020-11-30 17:11   ` Laurent Pinchart
2020-12-02 22:44     ` Dan Scally
2020-11-30 13:31 ` [PATCH 16/18] i2c: i2c-core-base: Use the new i2c_acpi_dev_name() in i2c_set_dev_name() Daniel Scally
2020-11-30 17:12   ` Laurent Pinchart
2020-11-30 19:18     ` Andy Shevchenko
2020-12-02  9:35       ` Andy Shevchenko
2020-12-02  9:49         ` Dan Scally
2020-12-01 23:50     ` Dan Scally
2020-11-30 13:31 ` [PATCH 17/18] gpio: gpiolib-acpi: Export acpi_get_gpiod() Daniel Scally
2020-11-30 19:20   ` Andy Shevchenko
2020-11-30 13:31 ` [PATCH 18/18] ipu3: Add driver for dummy INT3472 ACPI device Daniel Scally
2020-11-30 16:17   ` Jean-Michel Hautbois
2020-11-30 23:20     ` Dan Scally
2020-12-01 18:31       ` Andy Shevchenko
2020-12-01 18:36         ` Laurent Pinchart
2020-12-01 18:51           ` Andy Shevchenko
2020-11-30 16:29   ` Kieran Bingham
2020-11-30 17:21     ` Laurent Pinchart
2020-11-30 20:07   ` Andy Shevchenko
2020-11-30 23:32     ` Laurent Pinchart
2020-12-01 15:55       ` Sakari Ailus
2020-12-01 18:37         ` Laurent Pinchart
2020-12-02 11:09           ` Sakari Ailus
2020-12-02 12:42             ` Laurent Pinchart
2020-12-02 15:08               ` Andy Shevchenko
2020-12-03 12:37                 ` Dan Scally
2020-12-03 12:57                   ` Andy Shevchenko
2020-12-01 18:49       ` Andy Shevchenko
2020-12-01 20:59         ` Dan Scally
2020-12-02  9:39           ` Andy Shevchenko
2020-12-02 12:35             ` Laurent Pinchart
2020-12-02 15:11               ` Andy Shevchenko
2020-12-03 12:25             ` Dan Scally
2020-12-13 22:48         ` Daniel Scally
2020-12-14 15:33           ` Andy Shevchenko
2020-12-01  8:30     ` Dan Scally
2020-12-01 18:54       ` Andy Shevchenko
2020-12-01 18:55         ` Laurent Pinchart
2020-12-01 19:05           ` Andy Shevchenko
2020-12-01 19:06             ` Laurent Pinchart
2020-12-01 19:21               ` Andy Shevchenko
2020-12-01 20:34                 ` Hans de Goede
2020-12-02 12:48                   ` Laurent Pinchart
2020-12-02 15:15                     ` Andy Shevchenko [this message]
2020-12-01 21:05                 ` Dan Scally
2020-12-02  9:42                   ` Andy Shevchenko
2021-01-07 23:55     ` Daniel Scally
2021-01-08 12:17       ` [Devel] " Andy Shevchenko
2021-01-08 12:17         ` Andy Shevchenko
2021-01-08 23:24         ` Daniel Scally
2021-01-09  9:17           ` [Devel] " Andy Shevchenko
2021-01-09  9:58             ` Daniel Scally
2021-01-09  0:18         ` Laurent Pinchart
2021-01-09  0:39           ` Daniel Scally
2020-11-30 20:52   ` Sakari Ailus
2020-11-30 23:06     ` Dan Scally
2020-11-30 23:21       ` Laurent Pinchart
2020-12-01  0:05         ` Dan Scally
2020-12-01  6:44       ` Sakari Ailus
2020-12-01  8:08         ` Dan Scally
2020-12-01  8:09           ` Dan Scally
2020-12-01 12:32           ` Sakari Ailus
2020-12-01 12:40             ` Laurent Pinchart
2020-12-01 12:44               ` Sakari Ailus
2020-12-01 12:48             ` Dan Scally
2020-12-01 19:01               ` Andy Shevchenko
2020-12-01 18:55       ` Andy Shevchenko
  -- strict thread matches above, loose matches on Subject: below --
2020-11-30 16:45 [Devel] Re: [PATCH 13/18] ipu3-cio2: Add functionality allowing software_node connections to sensors on platforms designed for Windows kernel test robot
2020-11-30 16:45 ` kernel test robot
2020-11-30 16:45 ` kernel test robot
2020-11-30 17:02 [Devel] Re: [PATCH 17/18] gpio: gpiolib-acpi: Export acpi_get_gpiod() kernel test robot
2020-11-30 17:02 ` kernel test robot
2020-11-30 17:02 ` kernel test robot
2020-11-30 17:19 [Devel] Re: [PATCH 06/18] software_node: amend software_node_unregister_node_group() to perform unregistration of array in reverse order to be consistent with software_node_unregister_nodes() kernel test robot
2020-11-30 17:19 ` kernel test robot
2020-11-30 17:19 ` kernel test robot
2020-11-30 18:04 [Devel] Re: [PATCH 17/18] gpio: gpiolib-acpi: Export acpi_get_gpiod() kernel test robot
2020-11-30 18:04 ` kernel test robot
2020-11-30 18:04 ` kernel test robot
2020-11-30 20:27 [Devel] Re: [PATCH 13/18] ipu3-cio2: Add functionality allowing software_node connections to sensors on platforms designed for Windows kernel test robot
2020-11-30 20:27 ` kernel test robot
2020-11-30 20:27 ` kernel test robot
2020-12-01 20:45 [Devel] Re: [PATCH 18/18] ipu3: Add driver for dummy INT3472 ACPI device Andy Shevchenko
2020-12-01 20:46 ` Andy Shevchenko

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20201202151507.GH4077@smile.fi.intel.com \
    --to=andriy.shevchenko@linux.intel.com \
    --cc=bgolaszewski@baylibre.com \
    --cc=bingbu.cao@intel.com \
    --cc=devel@acpica.org \
    --cc=djrscally@gmail.com \
    --cc=erik.kaneda@intel.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=hdegoede@redhat.com \
    --cc=heikki.krogerus@linux.intel.com \
    --cc=jacopo+renesas@jmondi.org \
    --cc=jorhand@linux.microsoft.com \
    --cc=kieran.bingham+renesas@ideasonboard.com \
    --cc=kitakar@gmail.com \
    --cc=laurent.pinchart+renesas@ideasonboard.com \
    --cc=laurent.pinchart@ideasonboard.com \
    --cc=lenb@kernel.org \
    --cc=linus.walleij@linaro.org \
    --cc=linux-acpi@vger.kernel.org \
    --cc=linux-gpio@vger.kernel.org \
    --cc=linux-i2c@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-media@vger.kernel.org \
    --cc=linux@rasmusvillemoes.dk \
    --cc=mchehab@kernel.org \
    --cc=mika.westerberg@linux.intel.com \
    --cc=pmladek@suse.com \
    --cc=rjw@rjwysocki.net \
    --cc=robert.moore@intel.com \
    --cc=rostedt@goodmis.org \
    --cc=sakari.ailus@linux.intel.com \
    --cc=sergey.senozhatsky@gmail.com \
    --cc=tian.shu.qiu@intel.com \
    --cc=wsa@kernel.org \
    --cc=yong.zhi@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.