On 2018-12-18 19:15, Ben Greear wrote:
On 12/18/2018 05:12 AM, Johannes Berg wrote:
On Mon, 2018-12-03 at 17:34 +0530, vamsi krishna wrote:
NL80211_CMD_FRAME is used to send frames from userspace. Add support
to
transmit the frames at a rate specified by userspace when needed.
The drivers shall indicate the support to send frames at rate
specified
by userspace by setting %NL80211_EXT_FEATURE_CMD_FRAME_TXRATE flag in
wiphy capabilities. The userspace can specify the rate within
%NL80211_ATTR_RATE_INFO attribute while sending %NL80211_CMD_FRAME.
NL80211_ATTR_RATE_INFO is a nested attribute and encapsulates the
attributes defined in &enum nl80211_rate_info.
It'd be good if you were to repost this with a driver that uses it.
Unfortunately, the driver that I am working now is not upstreamed. I
would like to check with Ben if he likes to propose a patch ath10k
driver that he is working on as I see he is also interested in this
feature. Please let me know if it is mandatory or good to have driver
implementation.
Also, please explain why you think userspace needs this? It's not like
it can make better rate decisions than the rate control algorithm,
right?
Yes, you are correct. Rate control algorithm will continue to be in the
lower layers only. This is mostly for testing and experimenting
purposes.
[NL80211_ATTR_SCHED_SCAN_MIN_RSSI] = { .type = NLA_NESTED },
+ [NL80211_ATTR_RATE_INFO] = { .type = NLA_NESTED },
This should use NLA_POLICY_NESTED(nl80211_rate_info_policy)
Thanks for pointing out this MACRO, I used it in my new version of the
patch.
I missed the first posting of this patch. Here are some of my own
suggestions.
The wave-2 ath10k firmware has an option to specify tx-power, preamble
(CCK, OFDM, HT, VHT), bandwidth, mcs, nss and retry-count on a
per-packet
basis. This is not enabled in the ath10k driver, and I am not certain
QCA
firmware compiles in this option, but I have both ath10k-ct driver and
firmware
able to do this currently.
For HT and VHT, the mcs is fairly obvious I think. For CCK and OFDM,
the
mcs is treated as an index into the CCK and OFDM rate tables.
So, maybe the patch could use these basic constructs instead of the
different flags/rates for MCS vs VHT_MCS vs HE_MCS?
I am not sure if I understand your comment correctly. If you are
proposing to remove the different attribute ids for MCS, VHT_MCS and
HE_MCS, I think that will lead to unnecessary confusion especially as we
have duplicate indices between different modes(for example between HT
and VHT). I believe it is better to keep this similar to reporting tx
and rx rates in NL80211_CMD_GET_STATION in order to avoid problems with
future technologies like EHT.
Or, do you want to be able to specify multiple different tx rates per
frame? wave-2 firmware that I have seen wouldn't support that, but I
guess newer stuff
could?
My intention is to add single rate only.
Either way, please at least consider adding retry-count and tx-power
to this API and I
can tie it into my ath10k-ct driver and firmware API.
Sure, I have added them in the newer version of the patch.
Though I used in-reply-to option with git send-email, still the patch
that I sent is coming in a new thread @
https://patchwork.kernel.org/patch/10752599/ . I am not sure if that is
because of subject change, I had to change the subject of the patch in
order to reflect the new additions done to the patch. Could you please
kindly guide me with the right process to send the new patch.
Thanks,
Vamsi
