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From: khilman@baylibre.com (Kevin Hilman)
To: linus-amlogic@lists.infradead.org
Subject: [PATCH v2 1/4] reset: Add support for the Amlogic Meson SoC Reset Controller
Date: Wed, 25 May 2016 19:42:59 -0700	[thread overview]
Message-ID: <m2iny1h74c.fsf@baylibre.com> (raw)
In-Reply-To: <1464169758-26975-2-git-send-email-narmstrong@baylibre.com> (Neil Armstrong's message of "Wed, 25 May 2016 11:49:15 +0200")

Neil Armstrong <narmstrong@baylibre.com> writes:

> This patch adds the platform driver for the Amlogic Meson SoC Reset
> Controller.
>
> The Meson8b and GXBB SoCs are supported.
>
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>

Maybe a question for Philipp, but when testog this version with the
stmmac ethernet driver on the Amlogic boards, I noticed that ->reset was
never getting called.

Turns out, the stmmac driver only uses reset_control_assert() and
reset_control_deassert(), both of which return -ENOTSUPP since this
driver doesn't provide ->assert or ->deassert, so the driver's ->reset()
never gets called.

I haven't looked into the reset framework in detail, but if there's only
a ->reset hook, I kind of expected that reset_control_deassert() would
use that instead of returning -ENOTSUPP.

If not, what's the proper way of handling hardware that only supports a
write-only reset pulse?  Should users of reset_control_* be adapted to
check if ->deassert returns -ENOTSUPP and call ->reset?

Kevin

WARNING: multiple messages have this Message-ID (diff)
From: khilman@baylibre.com (Kevin Hilman)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 1/4] reset: Add support for the Amlogic Meson SoC Reset Controller
Date: Wed, 25 May 2016 19:42:59 -0700	[thread overview]
Message-ID: <m2iny1h74c.fsf@baylibre.com> (raw)
In-Reply-To: <1464169758-26975-2-git-send-email-narmstrong@baylibre.com> (Neil Armstrong's message of "Wed, 25 May 2016 11:49:15 +0200")

Neil Armstrong <narmstrong@baylibre.com> writes:

> This patch adds the platform driver for the Amlogic Meson SoC Reset
> Controller.
>
> The Meson8b and GXBB SoCs are supported.
>
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>

Maybe a question for Philipp, but when testog this version with the
stmmac ethernet driver on the Amlogic boards, I noticed that ->reset was
never getting called.

Turns out, the stmmac driver only uses reset_control_assert() and
reset_control_deassert(), both of which return -ENOTSUPP since this
driver doesn't provide ->assert or ->deassert, so the driver's ->reset()
never gets called.

I haven't looked into the reset framework in detail, but if there's only
a ->reset hook, I kind of expected that reset_control_deassert() would
use that instead of returning -ENOTSUPP.

If not, what's the proper way of handling hardware that only supports a
write-only reset pulse?  Should users of reset_control_* be adapted to
check if ->deassert returns -ENOTSUPP and call ->reset?

Kevin

  parent reply	other threads:[~2016-05-26  2:42 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-25  9:49 [PATCH v2 0/4] Amlogic: Meson: Add reset controller Neil Armstrong
2016-05-25  9:49 ` Neil Armstrong
2016-05-25  9:49 ` Neil Armstrong
2016-05-25  9:49 ` [PATCH v2 1/4] reset: Add support for the Amlogic Meson SoC Reset Controller Neil Armstrong
2016-05-25  9:49   ` Neil Armstrong
2016-05-25  9:49   ` Neil Armstrong
2016-05-25 10:14   ` Philipp Zabel
2016-05-25 10:14     ` Philipp Zabel
2016-05-25 10:14     ` Philipp Zabel
2016-05-26  2:42   ` Kevin Hilman [this message]
2016-05-26  2:42     ` Kevin Hilman
2016-05-26 11:02     ` Philipp Zabel
2016-05-26 11:02       ` Philipp Zabel
2016-05-26 11:02       ` Philipp Zabel
2016-05-26 18:42       ` Kevin Hilman
2016-05-26 18:42         ` Kevin Hilman
2016-05-26 18:42         ` Kevin Hilman
2016-05-30 16:14         ` Philipp Zabel
2016-05-30 16:14           ` Philipp Zabel
2016-05-30 16:14           ` Philipp Zabel
2016-05-25  9:49 ` [PATCH v2 2/4] dt-bindings: reset: Add bindings for the " Neil Armstrong
2016-05-25  9:49   ` Neil Armstrong
2016-05-25  9:49   ` Neil Armstrong
2016-05-25  9:49   ` Neil Armstrong
2016-05-25 19:10   ` Rob Herring
2016-05-25 19:10     ` Rob Herring
2016-05-25 19:10     ` Rob Herring
2016-05-26  7:30     ` Neil Armstrong
2016-05-26  7:30       ` Neil Armstrong
2016-05-26  7:30       ` Neil Armstrong
2016-05-25  9:49 ` [PATCH v2 3/4] ARM64: dts: amlogic: Enable Reset Controller on GXBB-based platforms Neil Armstrong
2016-05-25  9:49   ` Neil Armstrong
2016-05-25  9:49   ` Neil Armstrong
2016-05-25  9:49   ` Neil Armstrong
2016-05-25  9:49 ` [PATCH v2 4/4] ARM: dts: amlogic: Enable Reset Controller on Meson8b platforms Neil Armstrong
2016-05-25  9:49   ` Neil Armstrong
2016-05-25  9:49   ` Neil Armstrong

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