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Date:   Tue, 7 Jun 2022 19:58:20 -0700
From:   Nathan Chancellor <nathan@kernel.org>
To:     Ping-Ke Shih <pkshih@realtek.com>
Cc:     tony0620emma@gmail.com, kvalo@kernel.org,
        Larry.Finger@lwfinger.net, linux-wireless@vger.kernel.org
Subject: Re: [PATCH] rtw88: 8821c: fix access const table of channel
 parameters
Message-ID: <YqAQTJqOTB2+242p@dev-arch.thelio-3990X>
References: <20220608020312.9663-1-pkshih@realtek.com>
MIME-Version: 1.0
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In-Reply-To: <20220608020312.9663-1-pkshih@realtek.com>
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On Wed, Jun 08, 2022 at 10:03:12AM +0800, Ping-Ke Shih wrote:
> We would like to make chip_info table const, but 8821c uses one field as
> a variable, and causes core dump. To fix this, move the field to another
> struct that can be read and written.
> 
> BUG: unable to handle page fault for address: ffffffffc09f52f4
> PGD 5b5215067 P4D 5b5215067 PUD 5b5217067 PMD 111f61067 PTE 8000000111e07161
> Oops: 0003 [#1] PREEMPT SMP NOPTI
> CPU: 6 PID: 436 Comm: NetworkManager Not tainted 5.18.0-rc7-debug-01822-g89d8f53ff6e7 #1 5cac31ca93432e53341863abfb3332fd98b144da
> Hardware name: HP HP Desktop M01-F1xxx/87D6, BIOS F.12 12/17/2020
> RIP: 0010:rtw8821c_phy_set_param+0x262/0x380 [rtw88_8821c]
> Code: e8 53 f3 c0 d6 48 8b 43 10 4c 8b 63 38 be 24 0a 00 00 48 89 df 48
>  8b 40 68 e8 3a f3 c0 d6 89 e9 be 28 0a 00 00 48 89 df d3 e8 <41> 89 84
>  24 54 01 00 00 48 8b 43 10 4c 8b 63 38 48 8b 40 68 e8 15
> RSP: 0018:ffffb08c417cb6f0 EFLAGS: 00010286
> RAX: 0000000064b80c1c RBX: ffff93d15a0120e0 RCX: 0000000000000000
> RDX: 0000000034028211 RSI: 0000000000000a28 RDI: ffff93d15a0120e0
> RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000001 R11: 0000000000000006 R12: ffffffffc09f51a0
> R13: ffff93d15a0156d0 R14: 0000000000000000 R15: 0000000000000001
> FS:  00007f4e9b73d1c0(0000) GS:ffff93d83ab80000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: ffffffffc09f52f4 CR3: 0000000103b9e000 CR4: 0000000000350ee0
> Call Trace:
>  <TASK>
>  rtw_core_start+0xbd/0x190 [rtw88_core de79d6bdfd083d102030858972032e5706726279]
>  rtw_ops_start+0x26/0x40 [rtw88_core de79d6bdfd083d102030858972032e5706726279]
>  drv_start+0x42/0x100 [mac80211 21e803d0ad10691f64c6c81ecc24c0c6c36e5d58]
>  ieee80211_do_open+0x2fb/0x900 [mac80211 21e803d0ad10691f64c6c81ecc24c0c6c36e5d58]
>  ieee80211_open+0x67/0x80 [mac80211 21e803d0ad10691f64c6c81ecc24c0c6c36e5d58]
>  __dev_open+0xdd/0x180
>  [...]
> 
> Fixes: 89d8f53ff6e7 ("wifi: rtw88: Fix Sparse warning for rtw8821c_hw_spec")
> Reported-by: Nathan Chancellor <nathan@kernel.org>
> Cc: Larry Finger <Larry.Finger@lwfinger.net>
> Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>

I don't actually use wireless on this machine but my boot finishes and I
don't see any crash:

Tested-by: Nathan Chancellor <nathan@kernel.org>

> ---
>  drivers/net/wireless/realtek/rtw88/main.h     |  6 +++---
>  drivers/net/wireless/realtek/rtw88/rtw8821c.c | 14 ++++++++------
>  2 files changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/net/wireless/realtek/rtw88/main.h b/drivers/net/wireless/realtek/rtw88/main.h
> index 0baaf5a32e82d..5d00c161162c3 100644
> --- a/drivers/net/wireless/realtek/rtw88/main.h
> +++ b/drivers/net/wireless/realtek/rtw88/main.h
> @@ -1233,9 +1233,6 @@ struct rtw_chip_info {
>  	const struct wiphy_wowlan_support *wowlan_stub;
>  	const u8 max_sched_scan_ssids;
>  
> -	/* for 8821c set channel */
> -	u32 ch_param[3];
> -
>  	/* coex paras */
>  	u32 coex_para_ver;
>  	u8 bt_desired_ver;
> @@ -1937,6 +1934,9 @@ struct rtw_hal {
>  
>  	enum rtw_sar_bands sar_band;
>  	struct rtw_sar sar;
> +
> +	/* for 8821c set channel */
> +	u32 ch_param[3];
>  };
>  
>  struct rtw_path_div {
> diff --git a/drivers/net/wireless/realtek/rtw88/rtw8821c.c b/drivers/net/wireless/realtek/rtw88/rtw8821c.c
> index 42841f5d502c2..025262a8970eb 100644
> --- a/drivers/net/wireless/realtek/rtw88/rtw8821c.c
> +++ b/drivers/net/wireless/realtek/rtw88/rtw8821c.c
> @@ -125,6 +125,7 @@ static void rtw8821c_phy_bf_init(struct rtw_dev *rtwdev)
>  
>  static void rtw8821c_phy_set_param(struct rtw_dev *rtwdev)
>  {
> +	struct rtw_hal *hal = &rtwdev->hal;
>  	u8 crystal_cap, val;
>  
>  	/* power on BB/RF domain */
> @@ -159,9 +160,9 @@ static void rtw8821c_phy_set_param(struct rtw_dev *rtwdev)
>  
>  	/* post init after header files config */
>  	rtw_write32_set(rtwdev, REG_RXPSEL, BIT_RX_PSEL_RST);
> -	rtwdev->chip->ch_param[0] = rtw_read32_mask(rtwdev, REG_TXSF2, MASKDWORD);
> -	rtwdev->chip->ch_param[1] = rtw_read32_mask(rtwdev, REG_TXSF6, MASKDWORD);
> -	rtwdev->chip->ch_param[2] = rtw_read32_mask(rtwdev, REG_TXFILTER, MASKDWORD);
> +	hal->ch_param[0] = rtw_read32_mask(rtwdev, REG_TXSF2, MASKDWORD);
> +	hal->ch_param[1] = rtw_read32_mask(rtwdev, REG_TXSF6, MASKDWORD);
> +	hal->ch_param[2] = rtw_read32_mask(rtwdev, REG_TXFILTER, MASKDWORD);
>  
>  	rtw_phy_init(rtwdev);
>  	rtwdev->dm_info.cck_pd_default = rtw_read8(rtwdev, REG_CSRATIO) & 0x1f;
> @@ -351,6 +352,7 @@ static void rtw8821c_set_channel_rxdfir(struct rtw_dev *rtwdev, u8 bw)
>  static void rtw8821c_set_channel_bb(struct rtw_dev *rtwdev, u8 channel, u8 bw,
>  				    u8 primary_ch_idx)
>  {
> +	struct rtw_hal *hal = &rtwdev->hal;
>  	u32 val32;
>  
>  	if (channel <= 14) {
> @@ -367,11 +369,11 @@ static void rtw8821c_set_channel_bb(struct rtw_dev *rtwdev, u8 channel, u8 bw,
>  			rtw_write32_mask(rtwdev, REG_TXFILTER, MASKDWORD, 0x00003667);
>  		} else {
>  			rtw_write32_mask(rtwdev, REG_TXSF2, MASKDWORD,
> -					 rtwdev->chip->ch_param[0]);
> +					 hal->ch_param[0]);
>  			rtw_write32_mask(rtwdev, REG_TXSF6, MASKLWORD,
> -					 rtwdev->chip->ch_param[1] & MASKLWORD);
> +					 hal->ch_param[1] & MASKLWORD);
>  			rtw_write32_mask(rtwdev, REG_TXFILTER, MASKDWORD,
> -					 rtwdev->chip->ch_param[2]);
> +					 hal->ch_param[2]);
>  		}
>  	} else if (channel > 35) {
>  		rtw_write32_mask(rtwdev, REG_ENTXCCK, BIT(18), 0x1);
> -- 
> 2.25.1
>