Fixing Broadcom Corporation BCM57765/57785 SDXC/MMC Card Reader

bcm57765or57785fix

Follow the WORKAROUND:
  1. Add a comand to /etc/rc.local, add the following line above "exit 0": 
        setpci -s 00:1c.2 0x50.B=0x41
  2. Add the same comand to /etc/apm/resume.d/21aspm (which does not exist yet):
        setpci -s 00:1c.2 0x50.B=0x41
  3. Add the following to /etc/modprobe.d/sdhci.conf:
          options sdhci debug_quirks2=4
  4. Re-generate initrd:
         sudo update-initramfs -u -k all
  5. Reboot or reload sdhci module:
         sudo rmmod sdhci-pci sdhci
         sudo modprobe sdhci
         sudo modprobe sdhci-pci

If SD card still not detected after reboot, type this in command line:
     $ sudo setpci -s 00:1c.2 0x50.B=0x41
Tested on Acer V5-171

Reference: 
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1307674
https://wiki.allensmith.net/kb:linux:14lts-bcm57765-bmc57785

Thank you！
itʼs very helpful.