As part of today's April 9 Patch Tuesday, Microsoft is rolling out more firmware updates to its Surface RT and Surface Pro tablet/PC hybrids.

The April cumulative update for Surface RT focuses almost entirely on Wi-Fi, according to Microsoft's Surface RT Update History page.

Fixes include:

Certain “Limited” connectivity issues resolved

Improves Wi-Fi to handle a wide range of access points

Resolves system crashes caused by certain Wi-Fi issues

The April firmware update is the fifth Surface RT cumulative update the company has made since Microsoft launched the Surface RT in the U.S. and Canada in late October 2012. A number of Surface RT users have been complaining for months that they've had problems connecting to Wi-Fi with their devices. (I, fortunately, have not been among them.) Four of the five firmware updates Microsoft has made to the Surface RT include Wi-Fi connectivity fixes.

The April 9 cumulative update for Surface Pro includes other fixes and driver updates. The full list (from the Microsoft Update page for Pro):

Resolves an issue with on screen touch navigation in the UEFI boot menu

Resolves some Surface Type and Touch cover connectivity issues

Support for 106/109 keyboards on North American Surface devices

Resolves an issue where toggling airplane mode would disable the Wi-Fi driver

(By the way, for those who were wondering about a Surface Pro update they got in late March, after last month's Patch Tuesday one, it was "a low level driver update to improve SSD performance during boot," according to the Microsoft history page.)

Microsoft made the Surface Pro available in the U.S. and Canada in early February. Today's April updates are the second set of firmware patches for the devices.

Microsoft auto-installs updates on Surface RT and Surface Pro via Windows Update. Updates are cumulative, so users will get all previous updates delivered. With Surface RTs, automatic updating is always on. With the Pros, Windows turns on automatic update during setup unless users decide to turn it off. (If you do so, you won't be notified when firmware updates are available.)

Even if automatic updating is turned on, users can opt to proactively grab the firmware updates before they receive notification of their availability using Windows Update on their devices via these steps. The updates should be available for installation around 1 p.m. ET or so today.

Microsoft officials previously told me that users of non-Surface Windows RT devices also can and should get updates (firmware and otherwise). A spokesperson told me a couple months ago: "OEMs can (and are) providing any needed firmware or driver updates using Windows Update. These updates are targeted to specific Windows RT models. Recommended OS updates are available to all Windows RT devices at the time they are published. End-user settings will determine whether they are installed automatically."