How can I get the MMC timing spec higher than sd high-speed?

[Tomáš Juřena]

Hello,

I am having difficulties with the MMC bus and the external SDIO wifi module. We are using the wifi module jody-w263 from U-blox with the OSD32MP1, and the communication with the module works, but it is quite slow. The wifi module is capable of SDR 104 and DDR50 communication speeds, but I add the support to the DTS, the communication is broken and the device returns the -110 while initializing.

How can I add support for higher speeds?

I attach the working dts, dmesg, ios and caps, and relevant schematic.

Any suggestion will be appreciated.

Best regards,

Tomáš.

[Tomáš Juřena]

Hello Bernard,

I have applied all three provided patches but the still no change. The boot log is attached.

[Bernard PUEL]

Hello Tomas,

I see this trace:

[  3.273770] mmci-pl18x 48004000.sdmmc: mmc_regulator_set_vqmmc: found vmmc voltage range of 3300000-3400000uV

Are you sure you have "vqmmc-supply = <&v1v8_ldo1>;" in your devicetree ?

[Tomáš Juřena]

Hello,

yes, this line is there. I am attaching the dts file, that is in the yocto build directory (i.e. <yocto_build>/tmp-glibc/work/stm32mp157c_tevogs_v3_mx-ostl-linux-gnueabi/linux-stm32mp/5.4.56-r0/linux-5.4.56/arch/arm/). I also attach the decompiled dts that I took from the build dir and the dtb itself so you can check it. The v1v8_ldo1 regulator has the phandle number 0x2b and the same value is referenced in the vqmmc-supply of the sdmmc@48004000 node.

p.s.: in the decompiled file I had found the max-frequency is 120 Mhz, so I guess it is the default value, if not specified in the dts.

[Bernard PUEL]

Hello Tomas,

Thanks for the information.

kindly apply this new debug patch on top of all the rest and send me back the log.

I think we are not so far be we are still missing one trick ...

[Tomáš Juřena]

Hi Bernard,

glad to hear that and thank you for your support.

The log is attached.

[Bernard PUEL]

new tentative patch + more traces in case of failure, please apply the 2 patches on top of previous ones.

[Tomáš Juřena]

The boot log.

[Bernard PUEL]

new debug trace. Thanks for your patience.

[Tomáš Juřena]

Hello Bernard,

I am sending the log with the last patch.