add uhci_hcd bug to README.md

[evhz] / README.md

diff --git a/README.md b/README.md
index 840cff4952517596a29b832a1e3a1ffdff9a4db1..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
 
@@ -12,6 +11,11 @@ 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.