Wen Gong <wgong@xxxxxxxxxxxxxx> wrote:
> For sdio chip, it is high latency bus, all the TX packet's content will
> be tranferred from HOST memory to firmware memory via sdio bus, then it
> need much more memory in firmware than low latency bus chip, for low
> latency chip, such as PCI-E, it only need to transfer the TX descriptor
> via PCI-E bus to firmware memory. For sdio chip, reduce the complexity of
> TX logic will help TX efficiency since its memory is limited, and it will
> reduce the TX circle's time of each packet and then firmware will have more
> memory for TX since TX complete also need memeory.
>
> This patch disable TX complete indication from firmware for htt data
> packet, it will not have TX complete indication from firmware to ath10k.
> It will cut the cost of bus bandwidth of TX complete and make the TX
> logic of firmware simpler, it results in significant performance
> improvement on TX path.
>
> Udp TX throughout is 130Mbps without this patch, and it arrives
> 400Mbps with this patch.
>
> The downside of this patch is the command "iw wlan0 station dump" will
> show 0 for "tx retries" and "tx failed" since all tx packet's status
> is success.
>
> This patch only effect sdio chip, it will not effect PCI, SNOC etc.
>
> Tested with QCA6174 SDIO with firmware
> WLAN.RMH.4.4.1-00017-QCARMSWPZ-1
>
> Signed-off-by: Wen Gong <wgong@xxxxxxxxxxxxxx>
> Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
This has new warnings:
drivers/net/wireless/ath/ath10k/htt_tx.c: In function 'ath10k_htt_htc_tx_complete':
drivers/net/wireless/ath/ath10k/htt_tx.c:566:30: warning: 'msg_type' may be used uninitialized in this function [-Wmaybe-uninitialized]
drivers/net/wireless/ath/ath10k/htt_tx.c:573:6: warning: 'flags1' may be used uninitialized in this function [-Wmaybe-uninitialized]
drivers/net/wireless/ath/ath10k/htt_tx.c:577:42: warning: 'desc_hdr' may be used uninitialized in this function [-Wmaybe-uninitialized]
>From what I can see these are false positives, but please do double check that. In
the pending branch I solved it like this:
--- a/drivers/net/wireless/ath/ath10k/htt_tx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_tx.c
@@ -546,9 +546,9 @@ void ath10k_htt_htc_tx_complete(struct ath10k *ar, struct sk_buff *skb)
struct ath10k_htt *htt = &ar->htt;
struct htt_tx_done tx_done = {0};
struct htt_cmd_hdr *htt_hdr;
- struct htt_data_tx_desc *desc_hdr;
- u16 flags1;
- u8 msg_type;
+ struct htt_data_tx_desc *desc_hdr = NULL;
+ u16 flags1 = 0;
+ u8 msg_type = 0;
if (htt->disable_tx_comp) {
htt_hdr = (struct htt_cmd_hdr *)skb->data;
--
https://patchwork.kernel.org/patch/11377827/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
