linux-kernel - [PATCH v2 RFC 1/9] wifi: rtw88: Clear RTW_FLAG_POWERON early in rtw_mac_power

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Message-Id: <20230310202922.2459680-2-martin.blumenstingl@googlemail.com>
Date:   Fri, 10 Mar 2023 21:29:14 +0100
From:   Martin Blumenstingl <martin.blumenstingl@...glemail.com>
To:     linux-wireless@...r.kernel.org
Cc:     Yan-Hsuan Chuang <tony0620emma@...il.com>,
        Kalle Valo <kvalo@...nel.org>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        linux-kernel@...r.kernel.org, netdev@...r.kernel.org,
        linux-mmc@...r.kernel.org, Chris Morgan <macroalpha82@...il.com>,
        Nitin Gupta <nitin.gupta981@...il.com>,
        Neo Jou <neojou@...il.com>, Pkshih <pkshih@...ltek.com>,
        Jernej Skrabec <jernej.skrabec@...il.com>,
        Martin Blumenstingl <martin.blumenstingl@...glemail.com>
Subject: [PATCH v2 RFC 1/9] wifi: rtw88: Clear RTW_FLAG_POWERON early in rtw_mac_power_switch()

The SDIO HCI implementation needs to know when the MAC is powered on.
This is needed because 32-bit register access has to be split into 4x
8-bit register access when the MAC is not fully powered on or while
powering off. When the MAC is powered on 32-bit register access can be
used to reduce the number of transfers but splitting into 4x 8-bit
register access still works in that case.

During the power on sequence is how RTW_FLAG_POWERON is only set when
the power on sequence has completed successfully. During power off
however RTW_FLAG_POWERON is set. This means that the upcoming SDIO HCI
implementation does not know that it has to use 4x 8-bit register
accessors. Clear the RTW_FLAG_POWERON flag early when powering off the
MAC so the whole power off sequence is processed with RTW_FLAG_POWERON
unset. This will make it possible to use the RTW_FLAG_POWERON flag in
the upcoming SDIO HCI implementation.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@...glemail.com>
---
Changes since v1:
- This replaces a previous patch called "rtw88: hci: Add an optional
  power_switch() callback to rtw_hci_ops" which added a new callback
  to the HCI ops.

 drivers/net/wireless/realtek/rtw88/mac.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtw88/mac.c b/drivers/net/wireless/realtek/rtw88/mac.c
index f3a566cf979b..cfdfc8a2c836 100644
--- a/drivers/net/wireless/realtek/rtw88/mac.c
+++ b/drivers/net/wireless/realtek/rtw88/mac.c
@@ -273,6 +273,9 @@ static int rtw_mac_power_switch(struct rtw_dev *rtwdev, bool pwr_on)
 	if (pwr_on == cur_pwr)
 		return -EALREADY;

+	if (!pwr_on)
+		clear_bit(RTW_FLAG_POWERON, rtwdev->flags);
+
 	pwr_seq = pwr_on ? chip->pwr_on_seq : chip->pwr_off_seq;
 	ret = rtw_pwr_seq_parser(rtwdev, pwr_seq);
 	if (ret)
@@ -280,8 +283,6 @@ static int rtw_mac_power_switch(struct rtw_dev *rtwdev, bool pwr_on)

 	if (pwr_on)
 		set_bit(RTW_FLAG_POWERON, rtwdev->flags);
-	else
-		clear_bit(RTW_FLAG_POWERON, rtwdev->flags);

 	return 0;
 }
-- 
2.39.2