Subject: RE: [PATCH v4 07/11] wifi: rtw88: Add common USB chip support

From: Ping-Ke Shih <[email-masked]>
Date: Wed, 30 Nov 2022 01:40:36 +0000

> -----Original Message-----
> From: Sascha Hauer <[email-masked]>
> Sent: Tuesday, November 29, 2022 6:08 PM
> To: [email-masked]
> Cc: Neo Jou <[email-masked]>; Hans Ulli Kroll <[email-masked]>; Ping-Ke Shih <[email-masked]>;
> Yan-Hsuan Chuang <[email-masked]>; Kalle Valo <[email-masked]>; [email-masked];
> [email-masked]; Martin Blumenstingl <[email-masked]>;
> [email-masked]; Johannes Berg <[email-masked]>; Alexander Hochbaum <[email-masked]>;
> Da Xue <[email-masked]>; Bernie Huang <[email-masked]>; Viktor Petrenko <[email-masked]>;
> Sascha Hauer <[email-masked]>; neo_jou <[email-masked]>
> Subject: [PATCH v4 07/11] wifi: rtw88: Add common USB chip support
> 
> Add the common bits and pieces to add USB support to the RTW88 driver.
> This is based on https://github.com/ulli-kroll/rtw88-usb.git which
> itself is first written by Neo Jou.
> 
> Signed-off-by: neo_jou <[email-masked]>
> Signed-off-by: Hans Ulli Kroll <[email-masked]>
> Signed-off-by: Sascha Hauer <[email-masked]>
> ---
> 
> Notes:
>     Changes since v3:
>     - Add sanity break out of potentially endless loop
>     - Do not interleave PCI and USB support in Makefile
>     - fix rtwusb->usb_data_index locking
>     - make data_ptr variable in rtw_usb_tx_agg_skb() unnecessary
>     - Some coding style fixup
>     - drop set-but-unused variable in rtw_usb_write_data()
>     - Increase RTW_USB_MAX_RXQ_LEN to 512. I've seen "failed to get rx_queue, overflow\n"
>       trigger otherwise
> 
>     Changes since v2:
>     - Fix buffer length for aggregated tx packets
>     - Increase maximum transmit buffer size to 20KiB as found in downstream drivers
>     - Change register write functions to synchronous accesses instead of just firing
>       a URB without waiting for its completion
>     - requeue rx URBs directly in completion handler rather than having a workqueue
>       for it.
> 
>     Changes since v1:
>     - Make checkpatch.pl clean
>     - Drop WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL flag
>     - Use 'ret' as variable name for return values
>     - Sort variable declarations in reverse Xmas tree order
>     - Change potentially endless loop to a limited loop
>     - Change locking to be more obviously correct
>     - drop unnecessary check for !rtwdev
>     - make sure the refill workqueue is not restarted again after we have
>       cancelled it
> 
>  drivers/net/wireless/realtek/rtw88/Kconfig  |   3 +
>  drivers/net/wireless/realtek/rtw88/Makefile |   3 +
>  drivers/net/wireless/realtek/rtw88/mac.c    |   3 +
>  drivers/net/wireless/realtek/rtw88/main.c   |   4 +
>  drivers/net/wireless/realtek/rtw88/main.h   |   4 +
>  drivers/net/wireless/realtek/rtw88/reg.h    |   1 +
>  drivers/net/wireless/realtek/rtw88/tx.h     |  31 +
>  drivers/net/wireless/realtek/rtw88/usb.c    | 917 ++++++++++++++++++++
>  drivers/net/wireless/realtek/rtw88/usb.h    | 107 +++
>  9 files changed, 1073 insertions(+)
>  create mode 100644 drivers/net/wireless/realtek/rtw88/usb.c
>  create mode 100644 drivers/net/wireless/realtek/rtw88/usb.h
> 

[...]

> +static void rtw_usb_write_port_tx_complete(struct urb *urb)
> +{
> +	struct rtw_usb_txcb *txcb = urb->context;
> +	struct rtw_dev *rtwdev = txcb->rtwdev;
> +	struct ieee80211_hw *hw = rtwdev->hw;
> +	int max_iter = RTW_USB_MAX_XMITBUF_SZ;
> +
> +	while (true) {
> +		struct sk_buff *skb = skb_dequeue(&txcb->tx_ack_queue);
> +		struct ieee80211_tx_info *info;
> +		struct rtw_usb_tx_data *tx_data;
> +
> +		if (!skb)
> +			break;
> +
> +		if (!--max_iter) {

Don't you need to free 'skb'? or you should not dequeue skb in this situation?

> +			rtw_err(rtwdev, "failed to empty TX ack queue\n");
> +			break;
> +		}
> +
> +		info = IEEE80211_SKB_CB(skb);
> +		tx_data = rtw_usb_get_tx_data(skb);
> +
> +		/* enqueue to wait for tx report */
> +		if (info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS) {
> +			rtw_tx_report_enqueue(rtwdev, skb, tx_data->sn);
> +			continue;
> +		}
> +
> +		/* always ACK for others, then they won't be marked as drop */
> +		ieee80211_tx_info_clear_status(info);
> +		if (info->flags & IEEE80211_TX_CTL_NO_ACK)
> +			info->flags |= IEEE80211_TX_STAT_NOACK_TRANSMITTED;
> +		else
> +			info->flags |= IEEE80211_TX_STAT_ACK;
> +
> +		ieee80211_tx_status_irqsafe(hw, skb);
> +	}
> +
> +	kfree(txcb);
> +}
> +

[...]

I have reviewed patchset v4, and only one comment.

--
Ping-Ke