Elie De Brauwer wrote: > On 01/24/11 09:15, tiejun.chen wrote: >> Elie De Brauwer wrote: >>> On 01/24/11 04:26, tiejun.chen wrote: >>>> Elie De Brauwer wrote: >>>>> Hello list, >>>>> >>>>> I have a P2020 processor on a custom board which uses the embedded >>>>> fsl-esdhc controller. Hardware-wise this is functional and in u-boot >>>>> everything seems to behave (mmc part 0 gives the correct partition >>>>> table >>>>> and ext2ls/fatls are capable of reading the contents of the sd card). >>>>> >>>>> However as soon as I start Linux (2.6.36), I get all sorts of unwanted >>>>> behavior. Linux is unable to detect the partition layout (but if I >>>>> do a >>>> >>>> Can you re-partition that under Linux? i.e, you can use fdisk to do >>>> this. Then >>>> I'm a bit curious what it'll be happened. >>> >>> This was already partitioned under (x86) Linux, and when I plug it into >> >> I means you should partition the disk on the PPC Linux, not x86. As >> you know x86 >> work with LE for Linux, but PPC with BE. So I think you should >> partition that on >> the same type machine. Can you try it? >> >>> my laptop it sees the MBR (but also on target, in U-boot, the mmc part 0 >>> command shows the correct partition table). And this does not explain >> >> I didn't check this implemented codes within u-boot. Maybe u-boot can do >> something to swap MMC ending problem. You can try to get the >> conclusion. Firstly >> you can re-partition that on PPC Linux then check if u-boot can >> identify it >> properly. I guess u-boot still can read that successfully. >> > > Unfortunately two wrongs don't make a right here. When I fdisk it on > target, then on target the partition gets detected, in u-boot it fails > (Unknown partition table). To be honest this was already the behavior > which I expected because the endianness swap was also seen for the card > registers. So I think something more fundamental is wrong (which in turn > smells like the "BIG_ENDIAN_32BIT_BYTE_SWAPPER" but this is used in a > very convincing way by the fsl-esdh driver...
As you said looks you can disable 'MMC_SDHCI_BIG_ENDIAN_32BIT_BYTE_SWAPPER' from the Kconfig to rebuild Linux since its unnecessary for your target. Tiejun > >> >>> why the card registers (such as the scr pasted below) also seem to have >>> their endianess swapped, which will result in other side-effects, such >>> as improper reading of card capabilities. >>> >>>> >>>>> hexdump of the MBR, I see the endianness is swapped (last 4 bytes >>>>> are aa >>>>> 55 00 00). Also when I try to obtain the card registers they show the >>>>> same behavior: >>>>> # cat ./devices/soc.0/ff72e000.sdhci/mmc_host/mmc0/mmc0:0001/scr >>>>> 0000b50200000000 >>>>> >>>>> While for comparison the same value on my (x86) laptop gives: >>>>> edb@lapedb:/sys/devices/pci0000:00/0000:00:1e.0/0000:15:00.2/mmc_host/mmc0/mmc0:0001$ >>>>> >>>>> >>>>> cat scr >>>>> 02b5000000000000 >>>>> >>>>> In my config I have the following set: >>>>> CONFIG_MMC_SDHCI=y >>>>> CONFIG_MMC_SDHCI_IO_ACCESSORS=y >>>>> CONFIG_MMC_SDHCI_BIG_ENDIAN_32BIT_BYTE_SWAPPER=y >>>>> # CONFIG_MMC_SDHCI_PCI is not set >>>>> CONFIG_MMC_SDHCI_OF=y >>>>> CONFIG_MMC_SDHCI_OF_ESDHC=y >>>> >>>> At least looks the config is fine. >>>> >>>> Tiejun >>>> >>> >>> >> > > _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
