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From: Tony Lindgren <tony@atomide.com>
To: Faiz Abbas <a0230074@ti.com>
Cc: Faiz Abbas <faiz_abbas@ti.com>,
	linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
	linux-omap@vger.kernel.org, mark.rutland@arm.com,
	robh+dt@kernel.org, bcousson@baylibre.com,
	ulf.hansson@linaro.org, adrian.hunter@intel.com
Subject: Re: [PATCH] ARM: dts: am57xx-idk: Remove support for voltage switching for SD card
Date: Thu, 2 May 2019 07:35:25 -0700	[thread overview]
Message-ID: <20190502143525.GP8007@atomide.com> (raw)
In-Reply-To: <50559611-a501-4331-c88b-5d05f6e756e9@ti.com>

* Faiz Abbas <a0230074@ti.com> [190502 14:30]:
> Hi Tony,
> 
> On 02/05/19 7:50 PM, Tony Lindgren wrote:
> > * Faiz Abbas <faiz_abbas@ti.com> [190502 01:48]:
> >> If UHS speed modes are enabled, a compatible SD card switches down to
> >> 1.8V during enumeration. If after this a software reboot/crash takes
> >> place and on-chip ROM tries to enumerate the SD card, the difference in
> >> IO voltages (host @ 3.3V and card @ 1.8V) may end up damaging the card.
> >>
> >> The fix for this is to have support for power cycling the card in
> >> hardware (with a PORz/soft-reset line causing a power cycle of the
> >> card). Since am571x-, am572x- and am574x-idk don't have this
> >> capability, disable voltage switching for these boards.
> >>
> >> The major effect of this is that the maximum supported speed
> >> mode is now high speed(50 MHz) down from SDR104(200 MHz).
> > 
> > This sounds a bit urgent, does it also need a stable tag or is
> > it safe to apply against any earlier kernels?
> > 
> 
> This should be good to apply on any previous releases.

OK applying both your MMC patches into fixes today.

Thanks,

Tony

      reply	other threads:[~2019-05-02 14:35 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-02  8:47 [PATCH] ARM: dts: am57xx-idk: Remove support for voltage switching for SD card Faiz Abbas
2019-05-02 14:20 ` Tony Lindgren
2019-05-02 14:30   ` Faiz Abbas
2019-05-02 14:35     ` Tony Lindgren [this message]

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