Johannes Berg <johannes@xxxxxxxxxxxxxxxx> writes: >> (Mentors and wireless folks, we're struggling a bit with adding trace >> events to the xHCI USB host controller driver. I'm trying to look at >> the ath6kl driver trace events as an example. We could use some help >> and/or advice.) > > Those were in turn modelled on mac80211, cfg80211 and/or iwlwifi, I > think; might be worth also looking there. In general though, it's all > pretty similar. Correct, I used your code as example. > The message tracing was really more of an after-thought in iwlwifi (and > ath6kl as well I guess) because we already had a lot of debug messages > and capturing it all together can be useful. > > However, tracing all the debug messages is actually fairly expensive, I > think in part because of the string formatting and in part because of > the always-max allocations in the ringbuffer. The reason why added message tracing to ath6kl was that I wanted to combine wpasupplicant, cfg80211 and ath6kl debug messages all into file with synchronised timestamps. In this case I wasn't actually concerned about performance at all. -- Kalle Valo -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
