Comment 15 for bug 1553688

Still present in bionic with HWE 18.04.2 (kernel 4.18.0-22).
Card reader fails with high-speed SDXC.

Confirmed upstream: https://bugzilla.kernel.org/show_bug.cgi?id=109231

lspci --nnk
01:00.0 SD Host controller [0805]: O2 Micro, Inc. SD/MMC Card Reader Controller [1217:8520] (rev 01)
 Subsystem: Dell SD/MMC Card Reader Controller [1028:062d]
 Kernel driver in use: sdhci-pci
 Kernel modules: sdhci_pci

dmesg:
[ 1.369287] sdhci-pci 0000:01:00.0: SDHCI controller found [1217:8520] (rev 1)
[ 1.371230] mmc0: Unknown controller version (3). You may experience problems.
[ 1.373523] mmc0: SDHCI controller on PCI [0000:01:00.0] using ADMA
.
.
.
[ 419.378067] mmc0: Tuning timeout, falling back to fixed sampling clock
[ 419.379875] mmc0: new ultra high speed SDR104 SDXC card at address 5048
[ 419.383087] mmcblk0: mmc0:5048 SD256 232 GiB
[ 419.386191] mmcblk0: p1
[ 429.519557] mmc0: Timeout waiting for hardware interrupt.
[ 429.519561] mmc0: sdhci: ============ SDHCI REGISTER DUMP ===========
[ 429.519566] mmc0: sdhci: Sys addr: 0x00000008 | Version: 0x00000603
[ 429.519571] mmc0: sdhci: Blk size: 0x00000200 | Blk cnt: 0x00000008
[ 429.519575] mmc0: sdhci: Argument: 0x00000008 | Trn mode: 0x0000003b
[ 429.519580] mmc0: sdhci: Present: 0x01ff0000 | Host ctl: 0x00000017
[ 429.519584] mmc0: sdhci: Power: 0x0000000f | Blk gap: 0x00000000
[ 429.519589] mmc0: sdhci: Wake-up: 0x00000000 | Clock: 0x00000007
[ 429.519593] mmc0: sdhci: Timeout: 0x0000000a | Int stat: 0x00000000
[ 429.519598] mmc0: sdhci: Int enab: 0x02ff008b | Sig enab: 0x02ff008b
[ 429.519602] mmc0: sdhci: AC12 err: 0x00000004 | Slot int: 0x00000000
[ 429.519607] mmc0: sdhci: Caps: 0x25bec8bf | Caps_1: 0x1000207f
[ 429.519612] mmc0: sdhci: Cmd: 0x0000123a | Max curr: 0x005800c8
[ 429.519616] mmc0: sdhci: Resp[0]: 0x00000900 | Resp[1]: 0x0742ff7f
[ 429.519621] mmc0: sdhci: Resp[2]: 0x325b5900 | Resp[3]: 0x80000900
[ 429.519624] mmc0: sdhci: Host ctl2: 0x0000800b
[ 429.519628] mmc0: sdhci: ADMA Err: 0x00000000 | ADMA Ptr: 0x3541f208
[ 429.519629] mmc0: sdhci: ============================================
[ 450.058602] mmc0: Tuning timeout, falling back to fixed sampling clock

See https://bugzilla.kernel.org/show_bug.cgi?id=109231#c12

Workaround updated to:
rmmod sdhci_pci sdhci sdhci_acpi
modprobe sdhci debug_quirks2="0x80000000"
modprobe sdhci_pci