Re: [PATCH] ARM: dts: bcm2711: Use bcm2711 compatible for sdhci

[Nicolas Saenz Julienne]

Hi Stephen,

On Mon Jan 20, 2020 at 11:59 AM, Stephen Brennan wrote:
> Hi Nicolas,
>
> You're right, this patch doesn't work (it doesn't even touch the correct
> device tree node). My bad.
>
> > Your UHS class 1 card should work out of the box using the current
> > kernel version.
>
> I've been debugging an issue (reproduced on today's linux-next) in which
> my
> UHS class 1 card's partitions don't show up in `/dev`. For example, if I
> do
> `ls /dev | grep mmc`, I get just one result, "mmcblk1". I thought my
> patch
> fixed the issue, but it turns out that the issue is sporadic: on some
> boots, the issue manifests. On others, the partitions appear in /dev as
> normal. When I tested this patch, the issue had sporadically
> disappeared,
> leading me to believe the patch was effective.

Have you been playing with different device-trees? notably with the
Raspberry Pi foundation ones. Your mmc numbers could change, which might
be confusing.

If 100% sure it's failing, i.e. nothing happens for the mmc device after
seeing:

	mmc1: SDHCI controller on fe340000.emmc2 [fe340000.emmc2] using ADMA

I suggest enabling some extra debug options. Build the kernel with
DYNAMIC_DEBUG enabled and add dyndbg="module sdhci +mfp; module mmc_core
+mfp" to your kernel command line. It'll be extremely verbose for the
working case, but we can compare both and try to find something fishy.

Note that I use two UHS class 1 cards myself without issue.

> Sorry for the noise!

On the contrary, the more we are the better :)

Regards,
Nicolas