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Message-id: <5BE8C6B9.1090609@samsung.com>
Date: Mon, 12 Nov 2018 09:18:01 +0900
From: Chanwoo Choi <cw00.choi@...sung.com>
To: Marek Szyprowski <m.szyprowski@...sung.com>,
linux-kernel@...r.kernel.org, linux-samsung-soc@...r.kernel.org
Cc: MyungJoo Ham <myungjoo.ham@...sung.com>,
Krzysztof Kozlowski <krzk@...nel.org>,
Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>
Subject: Re: [PATCH 0/4] Fix common issue in MAX* extcon drivers
Hi Marek,
On 2018년 11월 08일 22:45, Marek Szyprowski wrote:
> Hi All
>
> Most MAX* MUIC drivers unconditionally force UART path during probe.
> This approach causes some issues, especially when board is booted with
> non-UART cable connected to micro-USB port. For example, when USB cable is
> connected, UART TX/RX lines are unconditionally short-circuited to USB
> D+/D- lines. This is in turn recognized by a series of serial BREAK
> signals and some random characters when USB host tries to perform
> enumeration procedure.
>
> To solve the above issue and keep UART console operational as early as
> possible, set UART path only when USB ID reports UART capable cable.
>
> This patchset fixes following MAX* extcon drivers: 8997, 14577, 77693
> and 77843.
>
> Tested on following Samsung boards: Trats (8997), Rinato (14577), Trats2
> (77693) and TM2/TM2e (77843).
>
> Best regards
> Marek Szyprowski
> Samsung R&D Institute Poland
>
>
> Patch summary:
>
> Marek Szyprowski (4):
> extcon: max77843: Avoid forcing UART path on drive probe
> extcon: max77693: Avoid forcing UART path on drive probe
> extcon: max14577: Avoid forcing UART path on drive probe
> extcon: max8997: Avoid forcing UART path on drive probe
>
> drivers/extcon/extcon-max14577.c | 15 +++++++++++++--
> drivers/extcon/extcon-max77693.c | 16 ++++++++++++++--
> drivers/extcon/extcon-max77843.c | 18 +++++++++++++++---
> drivers/extcon/extcon-max8997.c | 15 +++++++++++++--
> 4 files changed, 55 insertions(+), 9 deletions(-)
>
Applied them. Thanks.
--
Best Regards,
Chanwoo Choi
Samsung Electronics
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