Red Hat Bugzilla – Bug 144801
pwc module unusable with smp kernel
Last modified: 2015-01-04 17:15:19 EST
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Description of problem:
When loading the module with "modprobe pwc" no error messages occur:
Jan 11 16:55:15 roadrunner kernel: pwc Philips webcam module version
Jan 11 16:55:15 roadrunner kernel: pwc Supports Philips PCA645/646,
PCVC675/680/690, PCVC720/730/740/750 & PCVC830/840.
Jan 11 16:55:15 roadrunner kernel: pwc Also supports the Askey VC010,
various Logitech Quickcams, Samsung MPC-C10 and MPC-C30,
Jan 11 16:55:15 roadrunner kernel: pwc the Creative WebCam 5 & Pro Ex,
SOTEC Afina Eye and Visionite VCS-UC300 and VCS-UM100.
Jan 11 16:55:15 roadrunner kernel: pwc Enabling power save on open/close.
Jan 11 16:55:15 roadrunner kernel: pwc Philips PCVC740K (ToUCam
Pro)/PCVC840 (ToUCam II) USB webcam detected.
Jan 11 16:55:15 roadrunner kernel: pwc Registered as /dev/video1.
Jan 11 16:55:15 roadrunner kernel: usbcore: registered new driver
But when I try to use my webcam with an application like gnomemeeting
it shows no picture and after trying to change the resolution or to
end the capturing the application doesn't react anymore. After killing
the application /var/log/messages shows something like this:
Jan 11 16:58:18 roadrunner kernel: pwc Closing video device: 239
frames received, dumped 0 frames, 239 frames with errors.
If I boot my machine with the normal (non smp) kernel all things work
well. The problem also exists in older FC3 kernel versions in the same
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Connect your Philips USB webcam
2. Boot with smp kernel
3. modprobe pwc
4. Try to use the webcam with an application like gnomemeeting
Actual Results: No picture,
application doesn't react anymore
Expected Results: Get the captured picture(s) don't lock the
application. Behave like without smp support.
Got rid of the problem using kernel parameter noapic. No other things
made trouble without this.