A firmware upgrade fixed Linux USB 3 suspend problems

I recently got a NEC/Renesas uPD720201 based USB 3 card. It worked perfectly in Windows 7 with the 3.0.23.0 driver. It also worked when I booted Ubuntu 15.10 Wily Werewolf, but sometimes failed after suspend to ram (sleep) and sometimes prevented sleep. Upgrading to the latest development version, Ubuntu 16.04 LTS Xenial Xerus, did not fix the problem. Here is what the kernel logged when sleep failed:

xhci_hcd 0000:03:00.0: WARN: xHC save state timeout
suspend_common(): xhci_pci_suspend+0x0/0x70 returns -110
pci_pm_suspend(): hcd_pci_suspend+0x0/0x30 returns -110
dpm_run_callback(): pci_pm_suspend+0x0/0x140 returns -110
PM: Device 0000:03:00.0 failed to suspend async: error -110
PM: Some devices failed to suspend, or early wake event detected

Once this happened all subsequent attempts to suspend failed the same way, and only rebooting might allow suspend to work again.

According to Device Manager in Windows, the USB controller firmware version was 2020. Renesas doesn't offer any official downloads, but 2024 and 2026 are available for download elsewhere. Upgrading to 2026 (sometimes shown as 2.0.2.6) via k2026fwup1.exe (SHA1: 44184f1379c061067ac23ac30055a2b04ddf3940) seems to have fixed the problem. I haven't had any problems with suspend or resume, and the USB 3 ports remain functional after many suspend and resume cycles.

This probably also affects uPD720202, which is the same chip but with only two USB ports. The Renesas uPD720200 chip uses different firmware.

Some people reported problems with the 2026 upgrade procedure. Here someone recommends a 2024 downgrade followed by another 2026 upgrade if there are problems. I uninstalled the USB 3 driver in Windows 7 before the upgrade, thinking stuff that the driver does might interfere. The upgrade was quick and problem-free for me, and after rebooting I re-installed the driver.

BTW Here's a photo of the card: