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

Ping-Ke Shih
2022-11-30T01:41:40Z

> -----Original Message-----
> From: Sascha Hauer <s.hauer@pengutronix.de>
> Sent: Tuesday, November 29, 2022 6:08 PM
> To: linux-wireless@vger.kernel.org
> Cc: Neo Jou <neojou@gmail.com>; Hans Ulli Kroll <linux@ulli-kroll.de>; Ping-Ke Shih <pkshih@realtek.com>;
> Yan-Hsuan Chuang <tony0620emma@gmail.com>; Kalle Valo <kvalo@kernel.org>; netdev@vger.kernel.org;
> linux-kernel@vger.kernel.org; Martin Blumenstingl <martin.blumenstingl@googlemail.com>;
> kernel@pengutronix.de; Johannes Berg <johannes@sipsolutions.net>; Alexander Hochbaum <alex@appudo.com>;
> Da Xue <da@libre.computer>; Bernie Huang <phhuang@realtek.com>; Viktor Petrenko <g0000ga@gmail.com>;
> Sascha Hauer <s.hauer@pengutronix.de>; neo_jou <neo_jou@realtek.com>
> 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 <neo_jou@realtek.com>
> Signed-off-by: Hans Ulli Kroll <linux@ulli-kroll.de>
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> ---
>
> 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