Hi Fedor, thanks for review,
On Sat, May 17, 2025 at 03:21:03PM +0300, Fedor Pchelkin wrote:
> On Sat, 17. May 09:40, Stanislaw Gruszka wrote:
> > Move rate_idx range check after we add IL_FIRST_OFDM_RATE for it
> > for 5GHz band.
> >
> > Additionally use ">= RATE_COUNT" check instead of "> RATE_COUNT_LEGACY"
> > to avoid possible reviewers and static code analyzers confusion about
> > size of il_rate array.
> >
> > Reported-by: Fedor Pchelkin <pchelkin@xxxxxxxxx>
> > Reported-by: Alexei Safin <a.safin@xxxxxxx>
> > Signed-off-by: Stanislaw Gruszka <stf_xl@xxxxx>
> > ---
>
> Thank you for the patch, Stanislaw!
>
> Please see some comments below.
>
> > drivers/net/wireless/intel/iwlegacy/4965-mac.c | 15 +++++++++------
> > 1 file changed, 9 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/net/wireless/intel/iwlegacy/4965-mac.c b/drivers/net/wireless/intel/iwlegacy/4965-mac.c
> > index dc8c408902e6..2294ea43b4c7 100644
> > --- a/drivers/net/wireless/intel/iwlegacy/4965-mac.c
> > +++ b/drivers/net/wireless/intel/iwlegacy/4965-mac.c
> > @@ -1567,16 +1567,19 @@ il4965_tx_cmd_build_rate(struct il_priv *il,
> > /**
> > * If the current TX rate stored in mac80211 has the MCS bit set, it's
> > * not really a TX rate. Thus, we use the lowest supported rate for
> > - * this band. Also use the lowest supported rate if the stored rate
> > - * idx is invalid.
> > + * this band.
> > */
> > rate_idx = info->control.rates[0].idx;
> > - if ((info->control.rates[0].flags & IEEE80211_TX_RC_MCS) || rate_idx < 0
> > - || rate_idx > RATE_COUNT_LEGACY)
> > + if (info->control.rates[0].flags & IEEE80211_TX_RC_MCS)
> > rate_idx = rate_lowest_index(&il->bands[info->band], sta);
> > - /* For 5 GHZ band, remap mac80211 rate indices into driver indices */
> > - if (info->band == NL80211_BAND_5GHZ)
> > + else if (info->band == NL80211_BAND_5GHZ)
>
> 5GHZ shouldn't be in 'else if' clause, I think. Is it mutually exclusive
> with IEEE80211_TX_RC_MCS ?
Right, this is wrong. I thought we can use index returned by
rate_lowest_index() but we still should add IL_FIRST_OFDM_RATE.
At least this is how is done now.
>
> > + /* For 5 GHZ band, remap mac80211 rate indices into driver indices */
> > rate_idx += IL_FIRST_OFDM_RATE;
> > +
> > + /* Use the lowest supported rate if the stored rate idx is invalid. */
> > + if (rate_idx < 0 || rate_idx >= RATE_COUNT)
>
> There is a check inside il4965_rs_get_rate():
>
> /* Check for invalid rates */
> if (rate_idx < 0 || rate_idx >= RATE_COUNT_LEGACY ||
> (sband->band == NL80211_BAND_5GHZ &&
> rate_idx < IL_FIRST_OFDM_RATE))
> rate_idx = rate_lowest_index(sband, sta);
>
> so RATE_COUNT_LEGACY (60M) is considered invalid there but is accepted
> here in il4965_tx_cmd_build_rate(). It looks strange, at least for the
> fresh reader as me..
Indeed this is strange. I'm not sure why those checks differ.
Anyway for the rate_idx in il4965_tx_cmd_build_rate()
for 5GHs I'll just add additional check like below:
if (info->band == NL80211_BAND_5GHZ) {
rate_idx += IL_FIRST_OFDM_RATE;
if (rate_idx > IL_LAST_OFDM_RATE);
rate_idx = IL_LAST_OFDM_RATE;
}
This patch should be dropped.
Regards
Stanislaw
