2009/3/30 Fabio Rossi <rossi.f@xxxxxxxxx>: > On Sunday 29 March 2009, Nick Kossifidis wrote: > >> This patch introduces a function (and some helpers) to set 2 tables on >> hardware, it doesn't mess with the rest of the driver. I've tested it >> both on sta and ap scenarios with all the cards i have available and >> it worked fine. If you want to make more tests just disable parts of >> hw_txpower on phy.c, you can start by commenting out everything below >> >> ath5k_setup_rate_powertable(ah, txpower, &rate_info, ee_mode); >> >> to skip the setting of tx power, if you comment out the whole function >> you'll disable the functionality that this patch adds. > > I have discovered the problem. Inside ath5k_hx_txpower() it's called > ath5k_setup_channel_powertable() where the gain curves of frequency > piers are scanned (if I have understood correctly) to extract the data for > the calibration of the current channel. > > In particular, for the 5180MHz channel (the first of the A band), the function > ath5k_get_linear_pcdac_min() is called with some critical data which generate > an endless while loop. > > Here are the bad numbers passed to ath5k_get_linear_pcdac_min(): > * pwrL[0] = 4 > * pwrL[1] = 4 > * stepL[0] = 20 > * stepL[1] = 35 > and with this configuration the variable 'tmp' is never decremented inside the > first while loop. > > I suppose the data comes from the EEPROM. Is there an easy way to read the > contents of the EEPROM regarding the calibration data for all the channels? > > Fabio > Nice catch ;-) It's weird that your EEPROM contains a value twice, both pwrL[0] and pwrL[1] are 4 so interpolation always returns 4 and tmp is always > 1 so you have an endless loop. This is not what we expect to have on EEPROM (we are supposed to have a monotonicaly increasing curve and in your case it should be almost linear). Anyway since we have such cards we just need to put a check there and where pwrL[0] == pwrL[1], we set tmp = stepL[0] or if pwrR[0] == pwrR[1], we set tmp = stepR[0]. Try this out and see how it goes... -- GPG ID: 0xD21DB2DB As you read this post global entropy rises. Have Fun ;-) Nick -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
