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Message-ID: <be8f8f4c-4685-8ec9-9405-06a39327a36f@gmail.com>
Date: Thu, 2 Dec 2021 09:27:58 -0800
From: Florian Fainelli <f.fainelli@...il.com>
To: Al Cooper <alcooperx@...il.com>, linux-kernel@...r.kernel.org
Cc: Adrian Hunter <adrian.hunter@...el.com>,
bcm-kernel-feedback-list@...adcom.com,
Florian Fainelli <f.fainelli@...il.com>,
linux-arm-kernel@...ts.infradead.org, linux-mmc@...r.kernel.org,
Ray Jui <rjui@...adcom.com>,
Scott Branden <sbranden@...adcom.com>,
Ulf Hansson <ulf.hansson@...aro.org>
Subject: Re: [PATCH 1/2] mmc: sdhci-iproc: "mmc1: Internal clock never
stabilised." seen on 72113
On 12/2/21 8:30 AM, Al Cooper wrote:
> The problem is in the .shutdown callback that was added to the
> sdhci-iproc and sdhci-brcmstb drivers to save power in S5. The
> shutdown callback will just call the sdhci_pltfm_suspend() function
> to suspend the lower level driver and then stop the sdhci system
> clock. The problem is that in some cases there can be a worker
> thread in the "system_freezable_wq" work queue that is scanning
> for a device every second. In normal system suspend, this queue
> is suspended before the driver suspend is called. In shutdown the
> queue is not suspended and the thread my run after we stop the
> sdhci clock in the shutdown callback which will cause the "clock
> never stabilised" error. The solution will be to have the shutdown
> callback cancel the worker thread before calling suspend (and
> stopping the sdhci clock).
>
> NOTE: This is only happening on systems with the Legacy RPi SDIO
> core because that's the only controller that doesn't have the
> presence signal and needs to use a worker thread to do a 1 second
> poll loop.
>
> Fixes: 98b5ce4c08ca ("mmc: sdhci-iproc: Add support for the legacy sdhci controller on the BCM7211")
> Signed-off-by: Al Cooper <alcooperx@...il.com>
Acked-by: Florian Fainelli <f.fainelli@...il.com>
--
Florian
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