yongari 3f7fdc4947 Add simple MAC statistics counter reading support. Unfortunately ... useful counters like rl_missed_pkts is 16 bits quantity which is too small to hold meaningful information happened in a second. This means driver should frequently read these counters in order not to lose accuracy and that approach is too inefficient in driver's view. Moreover it seems there is no way to trigger an interrupt to detect counter near-full or wraparound event as well as lacking clearing the MAC counters. Another limitation of reading the counters from RealTek controllers is lack of interrupt firing at the end of DMA cycle of MAC counter read request such that driver have to poll the end of the DMA which is a time consuming process as well as inefficient. The more severe issue of the MAC counter read request is it takes too long to complete the DMA. All these limitation made maintaining MAC counters in driver impractical. For now, just provide simple sysctl interface to trigger reading the MAC counters. These counters could be used to track down driver issues. Users can read MAC counters maintained in controller with the following command. #sysctl dev.re.0.stats=1 While I'm here add check for validity of dma map and allocated memory before unloading/freeing them. Tested by: rmacklem		2010-11-05 19:28:00 +00:00
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if_re.c	Add simple MAC statistics counter reading support. Unfortunately	2010-11-05 19:28:00 +00:00