From: Chris Brandt <Chris.Brandt@renesas.com>
To: Biju Das <biju.das.jz@bp.renesas.com>,
Wolfram Sang <wsa+renesas@sang-engineering.com>,
Geert Uytterhoeven <geert+renesas@glider.be>,
Linux-Renesas <linux-renesas-soc@vger.kernel.org>
Cc: Phil Edworthy <phil.edworthy@renesas.com>,
Chris Paterson <Chris.Paterson2@renesas.com>
Subject: RE: Regarding SDHI clocks on RZ/G2L
Date: Tue, 20 Jul 2021 18:25:35 +0000 [thread overview]
Message-ID: <TYCPR01MB6319F7494FB5A69FB00AEA2A8AE29@TYCPR01MB6319.jpnprd01.prod.outlook.com> (raw)
In-Reply-To: <OS0PR01MB5922D113C4BF2C729B01497286E29@OS0PR01MB5922.jpnprd01.prod.outlook.com>
Hi Biju,
> -----Original Message-----
> From: Biju Das
> Sent: Tuesday, July 20, 2021 11:55 AM
> RZ/G2L document says we should not turn off cd clock during suspend.
> Otherwise card detection
From a hardware standpoint....yes.
> Won't work. So whether SDHI can reliably work in this case? Basically if
> there is no activity,
> this module can go into suspend state. If the cd clock turned off and card
> detection fails
> during resume, how the SDHI functionality going to work?
What I am saying is that from a system design standpoint, you need to wake up the system first before you can use the SD card (even detecting a card insert/remove).
> Note:-
> Currently I am configuring CD pin as gpio rather than function due to some
> reset issue[1]. After reset
> cd detection fails. But it works ok, if it configured as GPIO.
> 1) Handle it in SDHI driver? ie, enable it during probe only once and
> > avoid turning it off
> >
> > or
> >
> > 2) Add this clock as critical clock, so it will be turned on
> > permanently and don't handle it in SDHI driver?
So does that mean your #1 and #2 both do not work unless the pin is configured as GPIO?
Chris
next prev parent reply other threads:[~2021-07-20 18:26 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-18 10:25 Regarding SDHI clocks on RZ/G2L Biju Das
2021-07-20 14:47 ` Chris Brandt
2021-07-20 15:54 ` Biju Das
2021-07-20 18:25 ` Chris Brandt [this message]
2021-07-20 18:43 ` Biju Das
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