Hi, Can someone please point out the mistake in this example or provide some resources on how to disable a built-in driver on the Pocketbeagle using a suitable device tree overlay?
Thanks and regards Vaishnav On Thu 4 Jul, 2019, 11:21 PM Vaishnav MA, <mavaishnav...@gmail.com> wrote: > Hi, > > I have been working on the Google Summer of Code '19 Project: Click Board > <https://summerofcode.withgoogle.com/projects/#5996499987595264>Support > through Greybus > <https://summerofcode.withgoogle.com/projects/#5996499987595264>, which aims > to bring in support for MikroElektronika Click Boards > <https://www.mikroe.com/click> through Greybus Simulator > <https://github.com/projectara/gbsim> on the Pocketbeagle and Beaglebone > Black. I was able to add support for some of the Mikroe Click Boards > through the Greybus Simulator and more details about the project can be > found here: https://vaishnav98.github.io/GSoC19/ . I have been trying to > add support for the microSD(SPI Based) Click Board through Greybus > Simulator which is failing giving out the following error: > > [ 3621.614675] mmc1: unrecognised CSD structure version 2 > > complete error log at : https://github.com/vaishnav98/gbsim/issues/6 > > I went through the source code of the mmc (and mmc_spi) driver and found > that the corresponding error was thrown probably from here: > https://github.com/beagleboard/linux/blob/36fe81261dbfc1f751f7c1844e6ec5a36b594953/drivers/mmc/core/mmc.c#L149 > > > I am planning to debug the issue by printing out the card CSD data and to > verify if the data send is valid, for doing this I need to disable the > default mmc driver being loaded on that particular mmc controller so that > a new driver(with same functionality,additional printk calls) with a > different name can be loaded, for this i tried disabling the driver using a > Device Tree Overlay as mentioned in a previous thread for a different > driver(https://groups.google.com/forum/#!topic/beagleboard/bZFcV4y9QWQ). > However when I loaded the overlay (through /boot/uEnv.txt)and rebooted, the > pocketbeagle stopped booting. The overlay dts file I used are: > > /dts-v1/; > /plugin/; > > / { > > compatible = "ti,am335x-pocketbeagle", "ti,am335x-bone", "ti,am33xx"; > > fragment@0 { > target = <&mmc>; > > __overlay__ { > status = "disabled"; > > }; > }; > }; > > > and(separately) > > /dts-v1/; > /plugin/; > > / { > > compatible = "ti,am335x-pocketbeagle", "ti,am335x-bone", "ti,am33xx"; > > fragment@0 { > target = <&mmc1>; > > __overlay__ { > status = "disabled"; > > }; > }; > }; > > > dtc -W no-unit_address_vs_reg -@ -I dts -O dtb -o disablemmc.dtbo > disablemmc.dts > > > Can someone point out the mistake in the above DT overlay/ help me with > how to disable the default mmc driver loading up when a new microSD card is > instantiated through the Greybus Subsystem. It would also be really helpful > if someone could point out the meaning of the "unsupported CSD structure > version 2" from the mmc driver, I did some google search on the error and > could not find much useful information. (I have confirmed that the card and > the click board is working by loading the corresponding device tree overlay > for the Click board). > > Thanking You > > Vaishnav M A > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to beagleboard+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/beagleboard/176122a9-cc99-40c8-92a4-9adfd8d71e9b%40googlegroups.com > <https://groups.google.com/d/msgid/beagleboard/176122a9-cc99-40c8-92a4-9adfd8d71e9b%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CAFPGqouq4GtbF63gwriKerjgmo3xG8VQZWkwn3%3DtbpboO6Fxxw%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
