From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ww0-f45.google.com (mail-ww0-f45.google.com [74.125.82.45]) (using TLSv1 with cipher RC4-MD5 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 21D55B7111 for ; Mon, 24 Jan 2011 20:04:04 +1100 (EST) Received: by wwb29 with SMTP id 29so4367916wwb.14 for ; Mon, 24 Jan 2011 01:03:59 -0800 (PST) Message-ID: <4D3D407D.4080800@gmail.com> Date: Mon, 24 Jan 2011 10:03:57 +0100 From: Elie De Brauwer MIME-Version: 1.0 To: linuxppc-dev@lists.ozlabs.org Subject: Re: fsl-esdhc on P2020 weird endianess behavior References: <4D39B2B0.9050207@gmail.com> <4D3CF158.20704@windriver.com> <4D3D2FBB.6010504@gmail.com> <4D3D3512.4020105@windriver.com> In-Reply-To: <4D3D3512.4020105@windriver.com> Content-Type: text/plain; charset=UTF-8; format=flowed Cc: "tiejun.chen" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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... > >> 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 >>> >> >> > -- Elie De Brauwer