On 2012-04-16 11:44 AM, Felix Fietkau wrote: > On 2012-04-16 8:30 AM, Daniel Halperin wrote: >> On Sun, Apr 15, 2012 at 11:27 AM, Felix Fietkau <nbd@xxxxxxxxxxx> wrote: >>> On 2012-04-15 8:22 PM, Daniel Halperin wrote: >>>> Felix, >>>> >>>> This whole patch series throws the NICs out of spec compliance. For >>>> instance, page 626 of the 802.11-2007 standard (Table 17-15) says that >>>> aSIFStime is 32 us in 10 MHz mode and 64 us in 5 MHz mode. >>>> >>>> This might be okay to do for certain implementations (as, apparently, >>>> AR9280/AR9380), but will break compatibility with any device obeying >>>> the standard instead. >>>> >>>> (I wonder that, if this code below still works, then it seems that you >>>> might not be properly downclocking the chips' reference clock...) >>>> >>>> Are you aware there's a standard for this? Why violate it? >>> I'm aware that there's a standard for it, but if I put in the standard >>> values, the connection gets unreliable to the point where it's almost >>> unusable. That's why I chose to use existing products with 5/10 MHz >>> support as reference instead. >>> >> >> I hear you, but still suspect the bug's somewhere else. Violating the >> standard likely isn't the right choice unless you have a good >> reason... it sounds like you don't know why this is happening but this >> hack 'seems to work'. >> >> (UBNT is also ath-based, right? So it's not really proof that this >> hack doesn't break compatibility..) > Right, UBNT is also ath-based, and I dumped the registers on the device > to figure out what parameters they were using, and used those as > reference for my ath9k work. > I'm not aware of *any* standard compliant 5/10 MHz product out there, do > you know any? By the way, I'm doing some more testing and it seems like I may be able to get it working with standard compliant SIFS timing after all by tweaking the rx latency settings some more. John: Don't merge this series just yet, I'll send a v2 when I'm done testing. - Felix -- 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
