add uhci_hcd bug to README.md

[evhz] / README.md

diff --git a/README.md b/README.md
index 0c79187f696c8eaba62f6381b20284796056325b..780a9adb2c65699d57173c7c931ef0d3ea1c612a 100644 (file)
--- a/README.md
+++ b/README.md
@@ -1,7 +1,6 @@
-evhz
-====
+# evhz
 
-Display the current mouse refresh rate under linux with evdev.
+Display the current mouse refresh rate under linux with evdev
 
 For information about polling rate, see https://wiki.archlinux.org/index.php/Mouse_Polling_Rate
 
@@ -12,8 +11,14 @@ The program is just evhz.c. Compile and run:
 
 Nonverbose mode = -n
 
+There exists a kernel bug for USB ports which use the uhci_hcd driver,
+where a 1000 hz mouse will only read at 500hz, causing jittering:
+https://bugzilla.kernel.org/show_bug.cgi?id=60586. A workaround is to
+use USB ports that use the ehci-pci driver.
+
 Maintainer: Ian Kelling <ian@iankelling.org>
 
 Bugs, patches, requests, feedback are welcome.
 
-Last tested 7/2014 on Fedora 20. Still working great. 
\ No newline at end of file
+Last tested 7/2016 on Debian testing. Still working great after several
+years.