Re: eMMC boot problem: switch to bus width 8 ddr failed

[Jagan Teki]

On Fri, Jan 6, 2017 at 5:07 PM, Clemens Gruber
<clemens.gruber@xxxxxxxxxxxx> wrote:
> On Fri, Jan 06, 2017 at 10:54:35AM +0800, Shawn Lin wrote:
>> On 2017/1/6 8:41, Clemens Gruber wrote:
>> > Hi,
>> >
>> > with the current mainline 4.10-rc2 kernel, I can no longer boot from
>> > the eMMC on my i.MX6Q board.
>> >
>> > Details:
>> > The eMMC is a Micron MTFC4GACAJCN-1M WT but as the i.MX6Q only supports
>> > eMMC 4.41 features and we did not implement voltage switching from 3.3V
>> > to 1.8V or lower, I did add no-1-8-v; (but none of the mmc-ddr or mmc-hs
>> > options) to the device tree. The bus-width is 8.
>> >
>> > With 4.9 the board booted fine, now with the current mainline 4.10 tree,
>> > I get the following (repeating) errors at boot:
>> >
>> > [    4.326834] Waiting for root device /dev/mmcblk0p2...
>> > [   14.563861] mmc0: Timeout waiting for hardware cmd interrupt.
>> > [   14.569619] sdhci: =========== REGISTER DUMP (mmc0)===========
>> > [   14.575461] sdhci: Sys addr: 0x4e726000 | Version:  0x00000002
>> > [   14.581300] sdhci: Blk size: 0x00000200 | Blk cnt:  0x00000001
>> > [   14.587140] sdhci: Argument: 0x00010000 | Trn mode: 0x00000013
>> > [   14.592979] sdhci: Present:  0x01fd8009 | Host ctl: 0x00000031
>> > [   14.598816] sdhci: Power:    0x00000002 | Blk gap:  0x00000080
>> > [   14.604654] sdhci: Wake-up:  0x00000008 | Clock:    0x0000001f
>> > [   14.610493] sdhci: Timeout:  0x0000008f | Int stat: 0x00000000
>> > [   14.616332] sdhci: Int enab: 0x107f100b | Sig enab: 0x107f100b
>> > [   14.622168] sdhci: AC12 err: 0x00000000 | Slot int: 0x00000003
>> > [   14.628007] sdhci: Caps:     0x07eb0000 | Caps_1:   0x0000a007
>> > [   14.633845] sdhci: Cmd:      0x00000d1a | Max curr: 0x00ffffff
>> > [   14.639682] sdhci: Host ctl2: 0x00000000
>> > [   14.643611] sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0x4e6f7208
>> > [   14.649447] sdhci: ===========================================
>> >
>> > This repeats a few times, then more information is shown at the bottom:
>> >
>> > [   86.893859] mmc0: Timeout waiting for hardware cmd interrupt.
>> > [   86.899615] sdhci: =========== REGISTER DUMP (mmc0)===========
>> > [   86.905453] sdhci: Sys addr: 0x00000000 | Version:  0x00000002
>> > [   86.911291] sdhci: Blk size: 0x00000200 | Blk cnt:  0x00000001
>> > [   86.917129] sdhci: Argument: 0x00010000 | Trn mode: 0x00000013
>> > [   86.922967] sdhci: Present:  0x01fd8009 | Host ctl: 0x00000031
>> > [   86.928804] sdhci: Power:    0x00000002 | Blk gap:  0x00000080
>> > [   86.934642] sdhci: Wake-up:  0x00000008 | Clock:    0x0000001f
>> > [   86.940479] sdhci: Timeout:  0x0000008f | Int stat: 0x00000000
>> > [   86.946316] sdhci: Int enab: 0x107f100b | Sig enab: 0x107f100b
>> > [   86.952154] sdhci: AC12 err: 0x00000000 | Slot int: 0x00000003
>> > [   86.957992] sdhci: Caps:     0x07eb0000 | Caps_1:   0x0000a007
>> > [   86.963830] sdhci: Cmd:      0x00000d1a | Max curr: 0x00ffffff
>> > [   86.969668] sdhci: Host ctl2: 0x00000000
>> > [   86.973596] sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0x00000000
>> > [   86.979433] sdhci: ===========================================
>> > [   86.986356] mmc0: switch to bus width 8 ddr failed
>> > [   86.991163] mmc0: error -110 whilst initialising MMC card
>> > [   97.773859] mmc0: Timeout waiting for hardware cmd interrupt.
>> >
>> > --
>> >
>> > After looking through the latest commits to mmc/core, I found the
>> > culprit:
>> > Commit e173f8911f091fa50ccf8cc1fa316dd5569bc470 ("mmc: core: Update
>> > CMD13 polling policy when switch to HS DDR mode")
>> >
>> > Reverting it fixes the problem. But I am unsure if that's the right
>> > course of action?
>> >
>> > Feel free to send me patches for testing!
>> >
>>
>> I just look into both of sdhci and sdhci-esdhc-imx again, and seems the
>> code miss a bit, so could you also try this one?
>>
>> drivers/mmc/core/mmc_ops.c
>> @@ -486,7 +486,8 @@ static int mmc_poll_for_busy(struct mmc_card *card,
>> unsigned int timeout_ms,
>>                         busy = host->ops->card_busy(host);
>>                 } else {
>>                         err = mmc_send_status(card, &status);
>> -                       if (retry_crc_err && err == -EILSEQ) {
>> +                       if (retry_crc_err && (err == -EILSEQ ||
>> +                                               err == -ETIMEDOUT)) {
>>                                 busy = true;
>>                         } else if (err) {
>>                                 return err;
>>
>
> Hi,
>
> this patch (alone) does not solve the problem. The error message is the
> same as before.
>
> But applying both your first patch and this one does work. Is this one
> beneficial anyway, even if it does not fix my problem?

Able to detect the eMMC, but getting kernel panic while formatting the
disk, (even remove the mmc_ops change)

Log:
----
Disk /dev/mmcblk1: 3791 MB, 3791650816 bytes
4 heads, 16 sectors/track, 115712 cylinders
Units = cylinders of 64 * 512 = 32768 bytes

        Device Boot      Start         End      Blocks  Id System
/dev/mmcblk1p1               1      115712     3702776  83 Linux


Maximum filesystem blocks=4194304
29 block groups
32768 blocks per group, 32768 fragments per group
7984 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736
[  256.769236] Kernel panic - not syncing: Attempted to kill init!
exitcode=0x00000004
[  256.769236]
[  256.778779] ---[ end Kernel panic - not syncing: Attempted to kill
init! exitcode=0x00000004
[  256.778779]

Jagan.