On Wed, May 15, 2019 at 02:07:42PM +0200, Lorenzo Bianconi wrote: > > On Wed, May 15, 2019 at 01:13:49PM +0200, Lorenzo Bianconi wrote: > > > > On Wed, May 15, 2019 at 12:03:44PM +0200, Lorenzo Bianconi wrote: > > > > > > On Wed, May 15, 2019 at 11:43:55AM +0200, Lorenzo Bianconi wrote: > > > > > > > > On Mon, May 13, 2019 at 11:48:37AM +0200, Stanislaw Gruszka wrote: > > > > > > > > > On Mon, May 13, 2019 at 10:41:28AM +0200, Lorenzo Bianconi wrote: > > > > > > > > > > > Lorenzo Bianconi <lorenzo@xxxxxxxxxx> writes: > > > > > > > > > > > > > > > > > > > > > > > Introduce a knob in mt7603 debugfs in order to enable/disable > > > > > > > > > > > > edcca processing > > > > > > > > > > > > > > > > > > > > > > > > Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx> > > > > > > > > > > > > > > > > > > > > > > It's good to explain what edcca does and how the file is used supposed > > > > > > > > > > > to be used. In other words, have a small introduction for the user. > > > > > > > > > > > > > > > > > > > > Hi Kalle, > > > > > > > > > > > > > > > > > > > > edcca is used for adjusting energy detect based on CCA thresholds. > > > > > > > > > > The code was already there so I just reported the acronym. > > > > > > > > > > > > > > > > > > What for it is needed ? > > > > > > > > > > > > > > > > Care to comment why EDCCA is needed at all ? > > > > > > > > > > > > > > > > Taking that debugfs file that enable it is read-only, it looks like > > > > > > > > feature that nobody needs nor tests. > > > > > > > > > > > > > > already fixed in v2 > > > > > > > https://patchwork.kernel.org/patch/10940645/ > > > > > > > > > > > > I'm aware of this patch and other one for mt76x02. But so far in the > > > > > > sources EDCCA is disabled for mt76x02 without possibility to enable it > > > > > > (and this permission file issue was pointed by Kalle during review, not > > > > > > by someone who want to test EDCCA). So again, what for EDCCA is needed ? > > > > > > > > > > As I have already written in a previous email, ED/CCA is used to control tx power > > > > > according to the CCA MIB counters (e.g do not transmit if the channel busy time > > > > > is higher than 90% for given amount of time in a row). I guess it is required > > > > > by ETSI regulatory. > > > > But what is user case for that, i.e. who need this (it wasn't implemented in > > > > mt76x2 since you added it on Dec 2018). What will happen if it will be removed? > > > > > > > > > Regarding file permission for mt76x02 debugfs edcca node is a typo. > > > > Typo or not, effectively disable the feature and show nobody is > > > > testing it. > > > > > > > > The reason I'm asking is that seems EDCCA is the main reason to > > > > implement watchod for mt76x2, it wasn't necessary to have a watchdog > > > > as seems devices did not hung before EDCCA was added. > > > > > > IIRC I added the first watchdog implementation to fix tx hangs that occur > > > under heavy load even using FCC regulatory (so when EDCCA processing is > > > disabled) > > > > There was changes in various registers programming introduced by EDCCA > > support, even with EDCCA disabled. It's rally not convenient that > > watchdog and EDCCA are not related, since you added tx hung watchdog > > 2 weeks after adding EDCCA. > > > > You can look at this report: > > https://github.com/openwrt/mt76/issues/246 > > Before mt76x2e worked without hungs & watchodg. Now, even with EDCCA > > disabled watchdog and HW restarts are required to fix hungs on runtime. > > Tx hangs occur in very particular conditions (e.g 200Mbps bidirectional > traffic) and moreover they do not always occur so I am not convinced they > are always EDCCA related and so I am not confident to remove the watchdog I'm not opting for watchdog removal, but for full EDCCA removal. Apparently nobody cares, if it can be enabled or not. Stanislaw
