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From: Marek Vasut <marex@denx.de>
To: Lucas Stach <l.stach@pengutronix.de>,
	linux-arm-kernel@lists.infradead.org
Cc: ch@denx.de, Fabio Estevam <festevam@gmail.com>,
	Frieder Schrempf <frieder.schrempf@kontron.de>,
	NXP Linux Team <linux-imx@nxp.com>, Peng Fan <peng.fan@nxp.com>,
	Shawn Guo <shawnguo@kernel.org>
Subject: Re: [PATCH] soc: imx: gpcv2: Assert reset before ungating clock
Date: Sat, 17 Jul 2021 02:55:06 +0200	[thread overview]
Message-ID: <d08eb31b-27f7-ef21-d18b-875ded2e0232@denx.de> (raw)
In-Reply-To: <7685e3da21367e66057592fc003392abb0674dda.camel@pengutronix.de>

On 7/17/21 1:32 AM, Lucas Stach wrote:
> Hi Marek,

Hi,

> Am Donnerstag, dem 01.07.2021 um 00:59 +0200 schrieb Marek Vasut:
>> In case the power domain clock are ungated before the reset is asserted,
>> the system might freeze completely. However, the MX8MM GPUMIX and VPUMIX
>> domains require different reset deassertion timing, and incorrect reset
>> deassertion timing also leads to hang.
>>
>> Add per-domain reset_{,de}assert_early flags which allow fine-grained
>> control of the reset assertion and deassertion sequence. Currently, on
>> MX8MM, the behavior is as follows and aligned with NXP downstream ATF
>> fork:
>> - VPUMIX: reset assert, reset deassert, domain power up
>> - GPUMIX: reset assert, domain power on, reset deassert
>>
> This patch should now be necessary, as my testing over the last few
> days showed that the VPUMIX isn't actually different and copes just
> fine with the reset being asserted early, just like the GPUMIX domain.

Yes, this patch is absolutely essential, otherwise the system hangs at 
random, as explained in the commit message.

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  reply	other threads:[~2021-07-17  0:57 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-30 22:59 [PATCH] soc: imx: gpcv2: Assert reset before ungating clock Marek Vasut
2021-07-01  1:53 ` Peng Fan
2021-07-01  1:59   ` Marek Vasut
2021-07-16 23:32 ` Lucas Stach
2021-07-17  0:55   ` Marek Vasut [this message]
2021-07-17  9:07     ` Lucas Stach
2021-07-17 12:07       ` Marek Vasut
2021-07-19  8:46         ` Lucas Stach

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