On 08/25/2017 12:51 PM, Jes Sorensen wrote:
Hi,
Looking at some bits in rtlwifi I came across a discrepancy between the
PCI and USB code.
Consider the following code:
In rtl_pci_tx():
if (ieee80211_is_data_qos(fc)) {
tid = rtl_get_tid(skb);
if (sta) {
sta_entry = (struct rtl_sta_info *)sta->drv_priv;
seq_number = (le16_to_cpu(hdr->seq_ctrl) &
IEEE80211_SCTL_SEQ) >> 4;
seq_number += 1;
if (!ieee80211_has_morefrags(hdr->frame_control))
sta_entry->tids[tid].seq_number = seq_number;
}
In _rtl_usb_tx_preprocess():
if (ieee80211_is_data_qos(fc)) {
qc = ieee80211_get_qos_ctl(hdr);
tid = qc[0] & IEEE80211_QOS_CTL_TID_MASK;
seq_number = (le16_to_cpu(hdr->seq_ctrl) &
IEEE80211_SCTL_SEQ) >> 4;
seq_number += 1;
seq_number <<= 4;
}
[snip]
if (!ieee80211_has_morefrags(hdr->frame_control)) {
if (qc)
mac->tids[tid].seq_number = seq_number;
}
The seq_number is picked up from ieee80211_ops->ampdu_action()
which calls into rtl_tx_agg_start():
tid_data = &sta_entry->tids[tid];
RT_TRACE(rtlpriv, COMP_SEND, DBG_DMESG,
"on ra = %pM tid = %d seq:%d\n", sta->addr, tid,
tid_data->seq_number);
*ssn = tid_data->seq_number;
My question here is why does the USB code shift seq_number << 4 while
the PCI code doesn't? I assume one of these is wrong, but which one?
Based on my prejudices, I would suspect the USB driver before that of the PCI
version. I have BCc'd my contact at Realtek to see what he has to say on the issue.
Larry
