Hi Biju, > But on the SDHI driver, we are handing cd clocks for RZ/A devices. > Unfortunately we are turning of this clock > during suspend state. I think it is fine to shut off the cd clock in a suspend state because plug/unplug a SD card is not really something that should wake up a system. SHDI should not be a 'wake up' event source in a system, so we don't need it running during a suspend state. Things like interrupt pins and GPIO are wake up triggers. >From a power perspective, I don't think it will save much power to turn all the clocks off. So your #1 or #2 would be fine. As for #2, it's not really a 'critical clock' for the system.....it is more of a 'clock we don't care about'. I would say go with the one that is the easiest and makes the least code changes. If adding these to the SDHI driver make it very ugly, then we should just add them as critical clock and be done with it. That's my opinion. Chris > -----Original Message----- > From: Biju Das > Sent: Sunday, July 18, 2021 6:26 AM > To: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>; Geert Uytterhoeven > <geert+renesas@xxxxxxxxx>; Linux-Renesas <linux-renesas-soc@xxxxxxxxxxxxxxx> > Cc: Phil Edworthy <phil.edworthy@xxxxxxxxxxx>; Chris Brandt > <Chris.Brandt@xxxxxxxxxxx>; Chris Paterson <Chris.Paterson2@xxxxxxxxxxx> > Subject: Regarding SDHI clocks on RZ/G2L > > Hi All, > > As per the RZ/G2L clock list document, SDHI has 4 clocks and IMCLK2 should > not be turn off during suspend. > > 1)IMCLK Main Clock 1 > 2)IMCLK2 Main Clock 2, this clk should be not be turned off during suspend > state, otherwise card detection won't work. > 3)CLK_HS High speed clock > 4)ACLK Bus clock > > Multi clock PM domain support for SDHI is available in RZ/G2L and we are > filtering this clock not to add > PM domain. > > But on the SDHI driver, we are handing cd clocks for RZ/A devices. > Unfortunately we are turning of this clock > during suspend state. > > Q1) Is it expected behaviour for this device? > > Q2)What is the best way to handle cd clocks for RZ/G2L? > > 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? > > > Regards, > Biju
