Bug 12297
Summary: | Direct use of tsc: Analog joystick doesn't work properly with CPU frequency scaling activated | ||
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Product: | Drivers | Reporter: | Radoslaw Warowny (radoslaww) |
Component: | Input Devices | Assignee: | drivers_input-devices |
Status: | NEW --- | ||
Severity: | normal | CC: | alan, dik_again, jrnieder |
Priority: | P1 | ||
Hardware: | All | ||
OS: | Linux | ||
Kernel Version: | 3.12 | Subsystem: | |
Regression: | No | Bisected commit-id: |
Description
Radoslaw Warowny
2008-12-25 15:28:28 UTC
Hi Radek, Radek Warowny wrote: > I think the problem is located in analog kernel driver and is related > to usage of rdtscl() function to read time (in GET_TIME macro). This > function returns number of clock ticks, not real time. So when cpu [...] The driver hasn't changed much over time, so I suspect this still isn't fixed. If you are interested in fixing it, I think your best bet is writing a patch. If you make progress and then get stuck or want review, Vojtech Pavlik (the author) might still be reachable from <vojtech@suse.cz>; hopefully chapter 7 ("Time, Delays, and Deferred Work") of Linux Device Drivers at http://lwn.net/Kernel/LDD3/ would be helpful for getting vaguely acquainted with the facilities available. Sorry I have no better advice to offer. I confirm the bug. Analog joystick is unplayable on SB Live! gameport. I must change the cpugouverneut to performance, before loading the emu10k1-gp and analog modules. Probably the MIDI events for the music instruments is also affected by this. |