[PATCHv2 1/2] ARM: dts: socfpga: Fix SD card detect

Dinh,

On Mon, Oct 20, 2014 at 12:30 PM, Doug Anderson [off-list ref] wrote:

Dinh,

On Mon, Oct 20, 2014 at 9:31 AM, Dinh Nguyen
[off-list ref] wrote:

quoted

quoted

quoted

 &mmc0 {
-       cd-gpios = <&gpio1 18 0>;
+       cd = <&gpio1 18 0>;

This doesn't look right to me.  What was the error that was passed back?

I think your change has the same net effect as just deleting the
"cd-gpios" line.  ...or is there some code somewhere that is parsing
the "cd" property.

It just hangs here:

dw_mmc ff704000.dwmmc0: Using PIO mode.
dw_mmc ff704000.dwmmc0: Version ID is 240a
dw_mmc ff704000.dwmmc0: DW MMC controller at irq 171, 32 bit host data
width, 1024 deep fifo
platform ff704000.dwmmc0: Driver dw_mmc requests probe deferral


Without this patch :
mmc_of_parse ret=-517 (EPROBE_DEFER)

I think you need to dig more into this error.  Why are you getting an
-EPROBE_DEFER when you asked for this GPIO?

The -EPROBE_DEFER tells the system that a resource is not available
yet and that it should try to re-run the dw_mmc init later once the
resource becomes available.  I believe that some other bug is causing
the resource to never become available.

Guesses:

* The GPIO specifier is wrong in the DTB and is pointing to a GPIO
that would never exist.

* Something is happening in the GPIO driver that is causing it to fail.


...so we need to dig in further.

One odd thing is that it looks like the GPIO controller you're
referencing is disabled.  On today's linuxnext, you can see the
"disabled":

arch/arm/boot/dts/socfpga.dtsi:         gpio at ff709000 {
arch/arm/boot/dts/socfpga.dtsi-                 #address-cells = <1>;
arch/arm/boot/dts/socfpga.dtsi-                 #size-cells = <0>;
arch/arm/boot/dts/socfpga.dtsi-                 compatible = "snps,dw-apb-gpio";
arch/arm/boot/dts/socfpga.dtsi-                 reg = <0xff709000 0x1000>;
arch/arm/boot/dts/socfpga.dtsi-                 clocks = <&per_base_clk>;
arch/arm/boot/dts/socfpga.dtsi-                 status = "disabled";
arch/arm/boot/dts/socfpga.dtsi-
arch/arm/boot/dts/socfpga.dtsi-                 gpio1: gpio-controller at 0 {
arch/arm/boot/dts/socfpga.dtsi-                         compatible =
"snps,dw-apb-gpio-port";
arch/arm/boot/dts/socfpga.dtsi-                         gpio-controller;

I don't see anyone else referencing that node to enable it.  ...to me
that means that you can't use GPIOs on GPIO1 (???).


...or did I find something wrong?


-Doug