From: Raag Jadav <raag.jadav@intel.com>
To: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: "Rodrigo Vivi" <rodrigo.vivi@intel.com>,
"Matthew Brost" <matthew.brost@intel.com>,
"Thomas Hellström" <thomas.hellstrom@linux.intel.com>,
"Michael J . Ruhl" <michael.j.ruhl@intel.com>,
"Andy Shevchenko" <andriy.shevchenko@linux.intel.com>,
"Mika Westerberg" <mika.westerberg@linux.intel.com>,
"Riana Tauro" <riana.tauro@intel.com>,
"David Airlie" <airlied@gmail.com>,
"Simona Vetter" <simona@ffwll.ch>,
"Andi Shyti" <andi.shyti@kernel.org>,
dri-devel@lists.freedesktop.org, intel-xe@lists.freedesktop.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 3/3] drm/xe/mcu_i2c: Take over control of the controller enabling
Date: Tue, 30 Jun 2026 10:46:36 +0200 [thread overview]
Message-ID: <akOCbMKgTbzbZI7R@black.igk.intel.com> (raw)
In-Reply-To: <20260625125939.429078-4-heikki.krogerus@linux.intel.com>
On Thu, Jun 25, 2026 at 02:59:39PM +0200, Heikki Krogerus wrote:
> Some platforms make an assumption that the i2c controller's
> enabled state indicates also the power state of the
> controller. This can create a problem when the controller is
> in disabled state, because the hardware may assume
> incorrectly that it is then also in low-power state.
>
> To fix this, the controller is kept enabled by taking over
> the IC_ENABLE register. The controller has to be disabled
> when the configuration is updated and when the target
> address or the slave address are assigned, so disabling it
> when IC_CON, IC_TAR or IC_SAR registers are programmed, and
> then re-enabling it again.
I don't have enough context here, so I'll leave this one to the
maintainers.
Raag
prev parent reply other threads:[~2026-06-30 8:46 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-25 12:59 [PATCH v2 0/3] drm/xe/i2c: alerts and controller enabling modifications Heikki Krogerus
2026-06-25 12:59 ` [PATCH v2 1/3] i2c: designware: Global register definitions Heikki Krogerus
2026-06-25 14:30 ` Andy Shevchenko
2026-06-25 12:59 ` [PATCH v2 2/3] drm/xe/i2c: Handler for SMBus Alerts Heikki Krogerus
2026-06-30 8:39 ` Raag Jadav
2026-06-30 9:56 ` Heikki Krogerus
2026-06-30 10:28 ` Raag Jadav
2026-06-30 10:31 ` Heikki Krogerus
2026-06-25 12:59 ` [PATCH v2 3/3] drm/xe/mcu_i2c: Take over control of the controller enabling Heikki Krogerus
2026-06-30 8:46 ` Raag Jadav [this message]
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