Re: Problems after recent changes to meson-gx-mmc driver

[Jerome Brunet <jbrunet@baylibre.com>]

On Sat, 2017-09-09 at 15:14 +0200, Heiner Kallweit wrote:
> Hi Jerome,
> 
> the recent changes, most likely one of the changes affecting the clock phase
> setting
> or tuning, break mmc on my system (Odroid C2 + Hardkernel 128GB eMMC card).
> "Next" kernel from Aug 25th works fine here. Hadn't time yet to bisect the
> issue.
> 
> As additional info, that's what the eMMC DT config looks like here.
> The issue remains when switching to HS200.
> 
> /* eMMC */
> &sd_emmc_c {
>         status = "okay";
>         pinctrl-0 = <&emmc_pins>;
>         pinctrl-names = "default";
> 
>         bus-width = <8>;
>         cap-sd-highspeed;
>         max-frequency = <200000000>;
>         non-removable;
>         disable-wp;
>         cap-mmc-highspeed;
>         mmc-ddr-1_8v;
>         mmc-hs400-1_8v;

This is not the setup in the upstream dts.

>From what I see here, this emmc is using dual data rate modes.
So the most impacting change would be :

mmc: meson-gx: fix dual data rate mode frequencies

Before this patch the output frequency was actually half what was reported, so
in this case, I suspect you were only running at 100MHz before. At this
frequency, tuning on the emmc is a lot easier to achieve, if even necessary.

I have tested a fair amount of mmc configuration but I don't have setup with
HS400, but I think the following issue may rise:

* Generating 200MHz DDR output out of fdiv2 is not possible: this would require
400Mhz input which cannot be done from 1GHz and a simple divider. You can either
get 500Mhz (250Mhz out) or 250MHz (125MHz out)

* In HS400, If I remember correctly, tuning is done in HS200, then switch to
HS400 (bumping the input clock) May it require different phase setting ?

* Running 200MHz on the PCB is very demanding. I have seen that when trying
SDR104. Amplitude and signal quality drops significantly between 100MHz and
200Mhz. Are you sure the lines (including PCB, connectors, etc) are able to cope
with this and provide a good enough signal to the eMMC chip ?

Bottom line is that this eMMC never really run HS400, at least not at the speed
you thought it did. To get the rate you had previously, simply change this:

        max-frequency = <100000000>;



> 
>         mmc-pwrseq = <&emmc_pwrseq>;
>         vmmc-supply = <&vcc3v3>;
>         vqmmc-supply = <&vcc1v8>;
> };
> 
> Kind regards,
> Heiner
> 
> 
> [    0.784729] mmcblk0: mmc0:0001 DJNB4R 116 GiB
> [    0.790226] mmcblk0boot0: mmc0:0001 DJNB4R partition 1 4.00 MiB
> [    0.794860] mmcblk0boot1: mmc0:0001 DJNB4R partition 2 4.00 MiB
> [    0.800723] mmcblk0rpmb: mmc0:0001 DJNB4R partition 3 4.00 MiB
> [    0.807012]  mmcblk0: p1
> [    0.815910] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    0.818973] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    0.826699] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    0.836784] mmcblk0: error -110 sending stop command
> [    0.916784] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    0.920069] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    0.930234] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    0.933718] print_req_error: I/O error, dev mmcblk0, sector 2048
> [    0.939669] Buffer I/O error on dev mmcblk0p1, logical block 0, lost sync
> page write
> [    0.949190] EXT4-fs (mmcblk0p1): mounted filesystem with ordered data mode.
> Opts: (null)
> [    0.955397] VFS: Mounted root (ext4 filesystem) on device 179:1.
> [    0.963359] devtmpfs: mounted
> [    0.964411] Freeing unused kernel memory: 320K
> [    0.983379] mmcblk0: response CRC error sending SET_BLOCK_COUNT command,
> card status 0x900
> [    0.989571] mmcblk0: response CRC error sending r/w cmd command, card
> status 0x900
> [    1.093957] systemd[1]: System time before build time, advancing clock.
> [    1.159148] mmcblk0: response CRC error sending SET_BLOCK_COUNT command,
> card status 0x900
> [    1.193201] NET: Registered protocol family 10
> [    1.193750] Segment Routing with IPv6
> [    1.205032] systemd[1]: systemd 234 running in system mode. (+PAM -AUDIT
> -SELINUX -IMA -APPARMOR +SMACK -SYSVINIT +UTMP
> +LIBCRYP                                                                      
>                                                                       TSETUP
> +GCRYPT +GNUTLS +ACL +XZ +LZ4 +SECCOMP +BLKID +ELFUTILS +KMOD -IDN2 +IDN
> default-hierarchy=hybrid)
> [    1.220390] systemd[1]: Detected architecture arm64.
> [    1.244200] systemd[1]: Set hostname to <odroidc2>.
> [    1.370901] mmcblk0: response CRC error sending SET_BLOCK_COUNT command,
> card status 0x900
> [    1.378114] mmcblk0: response CRC error sending SET_BLOCK_COUNT command,
> card status 0x900
> [    1.397501] systemd[1]: Created slice User and Session Slice.
> [    1.415651] systemd[1]: Reached target Remote File Systems.
> [    1.432905] systemd[1]: Created slice System Slice.
> [    1.451645] systemd[1]: Reached target Slices.
> [    1.468022] systemd[1]: Created slice system-serial\x2dgetty.slice.
> [    1.483793] systemd[1]: Listening on udev Control Socket.
> [    1.502607] systemd[1]: Mounting Kernel Debug File System...
> [    1.830855] EXT4-fs (mmcblk0p1): re-mounted. Opts: data=ordered,discard
> [    2.077375] systemd-journald[644]: Received request to flush runtime
> journal from PID 1
> [    2.085030] systemd-journald[644]: File
> /var/log/journal/5d03187c26854bbe9eab8ea99e9291cb/system.journal corrupted or
> uncleanly                                                                     
>                                                                         shut
> down, renaming and replacing.
> [    2.096502] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    2.102475] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    2.110107] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    2.117608] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    2.125121] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    2.132627] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    2.140032] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    2.147511] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    2.155040] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    2.161860] print_req_error: I/O error, dev mmcblk0, sector 76224512
> [    2.168147] EXT4-fs warning (device mmcblk0p1): ext4_end_bio:322: I/O error
> 10 writing to inode 2359327 (offset 0 size 4096
> star                                                                          
>                                                                   ting block
> 9528065)
> [    2.181256] Buffer I/O error on device mmcblk0p1, logical block 9527808
> [    2.190050] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    2.196320] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    2.203573] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    2.211149] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    2.218616] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    2.226114] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    2.233593] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    2.241013] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    2.248513] mmcblk0: response CRC error sending r/w cmd command, card
> status 0xd00
> [    2.255350] print_req_error: I/O error, dev mmcblk0, sector 121899008
>