From: Jarkko Nikula <jarkko.nikula@linux.intel.com>
To: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
Cc: Hans de Goede <hdegoede@redhat.com>, Len Brown <lenb@kernel.org>,
Jani Nikula <jani.nikula@linux.intel.com>,
"russianneuromancer @ ya . ru" <russianneuromancer@ya.ru>,
linux-i2c@vger.kernel.org,
intel-gfx <intel-gfx@lists.freedesktop.org>
Subject: Re: [RFC 1/4] x86/platform/intel/iosf_mbi: Add a mutex for punit access
Date: Fri, 13 Jan 2017 13:12:15 +0200 [thread overview]
Message-ID: <d504f816-96f6-a745-e73c-eb0ea1bd8620@linux.intel.com> (raw)
In-Reply-To: <20170113105127.GH31595@intel.com>
On 01/13/2017 12:51 PM, Ville Syrjälä wrote:
> On Fri, Jan 13, 2017 at 12:34:54PM +0200, Jarkko Nikula wrote:
>> On 01/13/2017 11:26 AM, Ville Syrjälä wrote:
>>> It also feels quite hand wavy since the punit could do whatever at
>>> any time AFAIK. Eg. if there's some thermal event or something the
>>> punit might kick into action. So trying to protect this from the OS
>>> side might not be able to avoid these problems entirely. It feels like
>>> there really should be some kind of shared hardware/firmware mutex
>>> with the punit to arbitrate access to the i2c bus.
>>>
>> There is an HW semaphore for I2C access. It is implemented in
>> drivers/i2c/busses/i2c-designware-baytrail.c and another set from Hans
>> is adding support for Cherrytrail into it.
>
> Then why do we need anything else?
>
From this patch: "The punit on baytrail / cherrytrail systems is not
only accessed through the iosf_mbi functions, but also by the i915 code."
--
Jarkko
next prev parent reply other threads:[~2017-01-13 11:12 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-01 20:13 [RFC 0/4] Coordinate pmic i2c bus and i915 punit accesses Hans de Goede
2017-01-01 20:14 ` [RFC 1/4] x86/platform/intel/iosf_mbi: Add a mutex for punit access Hans de Goede
2017-01-02 14:12 ` Ville Syrjälä
2017-01-02 14:21 ` Hans de Goede
2017-01-13 9:26 ` Ville Syrjälä
2017-01-13 10:34 ` Jarkko Nikula
2017-01-13 10:51 ` Ville Syrjälä
2017-01-13 11:12 ` Jarkko Nikula [this message]
2017-01-13 12:20 ` Ville Syrjälä
2017-01-13 16:06 ` Hans de Goede
2017-01-13 16:30 ` Ville Syrjälä
2017-01-15 11:10 ` Hans de Goede
2017-01-01 20:14 ` [RFC 2/4] i2c: designware-baytrail: Take punit lock on bus acquire Hans de Goede
2017-01-01 20:14 ` [RFC 3/4] drm/i915: valleyview: Make intel_set_rps get FORCEWAKE_MEDIA Hans de Goede
2017-01-01 20:24 ` [Intel-gfx] " Chris Wilson
2017-01-01 20:48 ` Hans de Goede
2017-01-02 11:37 ` [Intel-gfx] " Chris Wilson
2017-01-02 12:40 ` Hans de Goede
2017-01-02 14:10 ` Ville Syrjälä
2017-01-02 14:21 ` Chris Wilson
2017-01-02 14:40 ` Ville Syrjälä
2017-01-02 14:53 ` [Intel-gfx] " Chris Wilson
2017-01-02 15:02 ` Ville Syrjälä
2017-01-02 15:08 ` Ville Syrjälä
2017-01-01 20:14 ` [RFC 4/4] drm/i915: valleyview: Take punit lock when modifying punit settings Hans de Goede
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=d504f816-96f6-a745-e73c-eb0ea1bd8620@linux.intel.com \
--to=jarkko.nikula@linux.intel.com \
--cc=hdegoede@redhat.com \
--cc=intel-gfx@lists.freedesktop.org \
--cc=jani.nikula@linux.intel.com \
--cc=lenb@kernel.org \
--cc=linux-i2c@vger.kernel.org \
--cc=russianneuromancer@ya.ru \
--cc=ville.syrjala@linux.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).