This issue was previously reported by another user on the Ubuntu bug tracker at https://bugs.launchpad.net/ubuntu/+source/linux/+bug/939548 but since I am not running Ubuntu it seemed more appropriate to report the bug here rather than reopen such an old issue elsewhere.

On a Lenovo ThinkPad T430 with the latest BIOS (G1ETA9WW - 2.69) running mainline Linux 4.3, after first boot lspci -nn shows:
02:00.0 System peripheral [0880]: Ricoh Co Ltd PCIe SDXC/MMC Host Controller [1180:e823] (rev 07)

After one or more warm reboots, lspci -nn shows:
02:00.0 System peripheral [0880]: Ricoh Co Ltd MMC/SD Host Controller [1180:e822] (rev 07)

This is not a significant problem for Linux, since either PCIID works, but it is an issue for Windows where the Lenovo/Ricoh driver only recognizes e823.  Doing a warm reboot from Linux to Windows causes Windows 7 to report a "Base System Device" without a driver and fail to recognize an inserted SD card.

I can confirm that Windows can be warm rebooted repeatedly and always reports e823.  Also, warm rebooting from Windows to Linux results in the same behavior as a cold boot (it reports e823 on first boot and e822 on subsequent boots, unless Linux had previously been booted in which case it reports e822).

Please let me know if there is anything that I can do to help debug.

Thanks,
Kevin