Re: [PATCH] ARM: dts: imx7ulp-evk: Use APLL_PFD1 as usdhc's clock source

[Fabio Estevam]

Hi Anson,

On Tue, Oct 29, 2019 at 7:06 AM Anson Huang <Anson.Huang@xxxxxxx> wrote:
>
> i.MX7ULP does NOT support runtime switching clock source for PCC,
> APLL_PFD1 by default is usdhc's clock source, so just use it
> in kernel to avoid below kernel dump during kernel boot up and
> make sure kernel can boot up with SD root file-system.
>
> [    3.035892] Loading compiled-in X.509 certificates
> [    3.136301] sdhci-esdhc-imx 40370000.mmc: Got CD GPIO
> [    3.242886] mmc0: Reset 0x1 never completed.
> [    3.247190] mmc0: sdhci: ============ SDHCI REGISTER DUMP ===========
> [    3.253751] mmc0: sdhci: Sys addr:  0x00000000 | Version:  0x00000002
> [    3.260218] mmc0: sdhci: Blk size:  0x00000200 | Blk cnt:  0x00000001
> [    3.266775] mmc0: sdhci: Argument:  0x00009a64 | Trn mode: 0x00000000
> [    3.273333] mmc0: sdhci: Present:   0x00088088 | Host ctl: 0x00000002
> [    3.279794] mmc0: sdhci: Power:     0x00000000 | Blk gap:  0x00000080
> [    3.286350] mmc0: sdhci: Wake-up:   0x00000008 | Clock:    0x0000007f
> [    3.292901] mmc0: sdhci: Timeout:   0x0000008c | Int stat: 0x00000000
> [    3.299364] mmc0: sdhci: Int enab:  0x007f010b | Sig enab: 0x00000000
> [    3.305918] mmc0: sdhci: ACmd stat: 0x00000000 | Slot int: 0x00008402
> [    3.312471] mmc0: sdhci: Caps:      0x07eb0000 | Caps_1:   0x0000b400
> [    3.318934] mmc0: sdhci: Cmd:       0x0000113a | Max curr: 0x00ffffff
> [    3.325488] mmc0: sdhci: Resp[0]:   0x00000900 | Resp[1]:  0x0039b37f
> [    3.332040] mmc0: sdhci: Resp[2]:   0x325b5900 | Resp[3]:  0x00400e00
> [    3.338501] mmc0: sdhci: Host ctl2: 0x00000000
> [    3.343051] mmc0: sdhci: ============================================
>
> Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>

Thanks, with this patch applied I can get SD card rootfs to get mounted:

Tested-by: Fabio Estevam <festevam@xxxxxxxxx>

I think this fix deserves a Fixes tag so that it can be backported to
older kernels.