[PATCH] [media] em28xx: fix Terratec Grabby AC97 codec detection

this proof by polling AC97_RESET until the expected value is read. We also check that unrelated registers don't return the same value. This second check handles the case where the expected value is constantly returned no matter which register is accessed. Signed-off-by: Matthieu

[PATCH] Fix Terratec Grabby AC97 codec detection

Thanks Mauro for commenting on my work. With respect to first version, I've: * added a timeout mecanism as requested * added an extra check to avoid cases when the same value is constantly returned no matter which register is accessed. --- To test this: * modprobe em28xx-alsa * connect Grabby * m