Re: [PATCH v2 00/40] Tegra SDHCI add support for HS200 and UHS signaling

[Marcel Ziswiler]

On Fri, 2018-08-10 at 21:08 +0300, Aapo Vienamo wrote:
> Hi all,
> 
> This series implements support for faster signaling modes on Tegra
> SDHCI controllers. This series consist of several parts: changes
> requried for 1.8 V signaling and pad control, pad calibration, and
> tuning. Following earlies patch sets have been merged into this
> larger set: "Tegra PMC pinctrl pad configuration", "Tegra SDHCI
> enable
> 1.8 V signaling on Tegar210 and Tegra186", "Tegra SDHCI update the
> padautocal procedure". Also the patches for enabling SDHCI tuning
> are added.

I tried your tkln/hs200 branch on Colibri T20, Apalis/Colibri T30 and
Apalis TK1. It at least does not seem to make things any worse but
HS200 on TK1 still seems to behave strangely. During boot I do get the
following message (mmc0 being the SDHCI instance of one of them SD card
slots):

[    3.238360] mmc0: Internal clock never stabilised.
[    3.243183] mmc0: sdhci: ============ SDHCI REGISTER DUMP
===========
[    3.249649] mmc0: sdhci: Sys addr:  0x00000000 |
Version:  0x00000303
[    3.256138] mmc0: sdhci: Blk size:  0x00000000 | Blk
cnt:  0x00000000
[    3.262657] mmc0: sdhci: Argument:  0x00000000 | Trn mode:
0x00000000
[    3.269119] mmc0: sdhci: Present:   0x01fb00f0 | Host ctl:
0x00000000
[    3.275580] mmc0: sdhci: Power:     0x0000000f | Blk
gap:  0x00000000
[    3.282041] mmc0: sdhci: Wake-up:   0x00000000 |
Clock:    0x00000401
[    3.288485] mmc0: sdhci: Timeout:   0x00000000 | Int stat:
0x00000000
[    3.295037] mmc0: sdhci: Int enab:  0x00ff0003 | Sig enab:
0x00fc0003
[    3.301559] mmc0: sdhci: AC12 err:  0x00000000 | Slot int:
0x00000000
[    3.308022] mmc0: sdhci: Caps:      0x376fd080 |
Caps_1:   0x10000f70
[    3.314527] mmc0: sdhci: Cmd:       0x00000000 | Max curr:
0x00000000
[    3.321159] mmc0: sdhci: Resp[0]:   0x00000000 |
Resp[1]:  0x00000000
[    3.327642] mmc0: sdhci: Resp[2]:   0x00000000 |
Resp[3]:  0x00000000
[    3.334144] mmc0: sdhci: Host ctl2: 0x00000000
[    3.338613] mmc0: sdhci: ADMA Err:  0x00000000 | ADMA Ptr:
0x00000000
[    3.345110] mmc0: sdhci:
============================================

And it subsequently stalls waiting for interrupt for more than 8
seconds before continuing to mount the rootfs as follows (mmc2 being
the SDHCI instance of the eMMC):

[    4.874017] tegra-hdmi 54280000.hdmi: cannot set audio to 48000 Hz
at 297000000 Hz pixel clock
[   13.930136] mmc2: Timeout waiting for hardware interrupt.
[   13.935603] mmc2: sdhci: ============ SDHCI REGISTER DUMP
===========
[   13.942071] mmc2: sdhci: Sys addr:  0x00000000 |
Version:  0x00000303
[   13.948511] mmc2: sdhci: Blk size:  0x00007080 | Blk
cnt:  0x00000001
[   13.954948] mmc2: sdhci: Argument:  0x00000000 | Trn mode:
0x00000013
[   13.961385] mmc2: sdhci: Present:   0x01fb00f0 | Host ctl:
0x00000031
[   13.967821] mmc2: sdhci: Power:     0x00000001 | Blk
gap:  0x00000000
[   13.974263] mmc2: sdhci: Wake-up:   0x00000000 |
Clock:    0x00000007
[   13.980692] mmc2: sdhci: Timeout:   0x0000000e | Int stat:
0x00000000
[   13.987119] mmc2: sdhci: Int enab:  0x02ff000b | Sig enab:
0x02fc000b
[   13.993546] mmc2: sdhci: AC12 err:  0x00000000 | Slot int:
0x00000000
[   13.999974] mmc2: sdhci: Caps:      0x376fd080 |
Caps_1:   0x10000f70
[   14.006415] mmc2: sdhci: Cmd:       0x0000153a | Max curr:
0x00000000
[   14.012845] mmc2: sdhci: Resp[0]:   0x00000b00 |
Resp[1]:  0x048062bf
[   14.019272] mmc2: sdhci: Resp[2]:   0x314a8000 |
Resp[3]:  0x00000240
[   14.025697] mmc2: sdhci: Host ctl2: 0x0000000b
[   14.030132] mmc2: sdhci: ADMA Err:  0x00000000 | ADMA Ptr:
0xfbc6b208
[   14.036561] mmc2: sdhci:
============================================
[   14.044332] mmc2: new HS200 MMC card at address 0001
[   14.050656] mmcblk2: mmc2:0001 016G30 14.7 GiB
[   14.056376] mmcblk2boot0: mmc2:0001 016G30 partition 1 4.00 MiB
[   14.063563] mmcblk2boot1: mmc2:0001 016G30 partition 2 4.00 MiB
[   14.069589] mmcblk2rpmb: mmc2:0001 016G30 partition 3 4.00 MiB,
chardev (247:0)
[   14.078260]  mmcblk2: p1 p2

After that it actually seems to work quite nicely:

root@apalis-tk1-mainline:~# cat /sys/kernel/debug/mmc2/ios
clock:          200000000 Hz
actual clock:   163200000 Hz
vdd:            21 (3.3 ~ 3.4 V)
bus mode:       2 (push-pull)
chip select:    0 (don't care)
power mode:     2 (on)
bus width:      3 (8 bits)
timing spec:    9 (mmc HS200)
signal voltage: 1 (1.80 V)
driver type:    0 (driver type B)
root@apalis-tk1-mainline:~# hdparm -t /dev/mmcblk2

/dev/mmcblk2:
 Timing buffered disk reads: 408 MB in  3.01 seconds = 135.39 MB/sec

Have you ever observed similar behaviour? What could cause this?

Anybody else tried it on TK1?