From: Chin-Yen Lee <timlee@xxxxxxxxxxx> [ Upstream commit 9496d62f3877bc0f97b415bc04af98d092878026 ] Sometimes driver can't use kernel API pci_read/write_config_byte to access the PCI config space of above address 0x100 due to the negotiated PCI setting. 8852AE/8852BE/8851BE provide another way called DBI function, which belongs to WiFi mac and could access all PCI config space for this case. Link: https://lore.kernel.org/linux-wireless/79fe81b7db7148b9a7da2353c16d70fb@xxxxxxxxxxx/T/#t Signed-off-by: Chin-Yen Lee <timlee@xxxxxxxxxxx> Signed-off-by: Ping-Ke Shih <pkshih@xxxxxxxxxxx> Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxx> Link: https://msgid.link/20240103012346.6822-1-pkshih@xxxxxxxxxxx Signed-off-by: Zenm Chen <zenmchen@xxxxxxxxx> --- Without this patch applied, the rtw89 driver in kernel 6.6.y may fail to initialize the RTL8852BE chip and print the error messages below on some platforms [1]. [ 13.449168] rtw89_8852be_git 0000:02:00.0: [ERR]pci config read 719 [ 13.449754] rtw89_8852be_git 0000:02:00.0: [ERR] pcie autok fail -22 [ 13.450353] rtw89_8852be_git 0000:02:00.0: failed to setup chip information [ 13.455857] rtw89_8852be_git: probe of 0000:02:00.0 failed with error -22 [1] https://github.com/a5a5aa555oo/rtw89/issues/3 --- drivers/net/wireless/realtek/rtw89/pci.c | 69 +++++++++++++++++++++++- drivers/net/wireless/realtek/rtw89/pci.h | 1 + 2 files changed, 68 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/realtek/rtw89/pci.c b/drivers/net/wireless/realtek/rtw89/pci.c index 30cc6e03c..33b2543ee 100644 --- a/drivers/net/wireless/realtek/rtw89/pci.c +++ b/drivers/net/wireless/realtek/rtw89/pci.c @@ -1822,22 +1822,87 @@ static int rtw89_write16_mdio_clr(struct rtw89_dev *rtwdev, u8 addr, u16 mask, u return 0; } +static int rtw89_dbi_write8(struct rtw89_dev *rtwdev, u16 addr, u8 data) +{ + u16 addr_2lsb = addr & B_AX_DBI_2LSB; + u16 write_addr; + u8 flag; + int ret; + + write_addr = addr & B_AX_DBI_ADDR_MSK; + write_addr |= u16_encode_bits(BIT(addr_2lsb), B_AX_DBI_WREN_MSK); + rtw89_write8(rtwdev, R_AX_DBI_WDATA + addr_2lsb, data); + rtw89_write16(rtwdev, R_AX_DBI_FLAG, write_addr); + rtw89_write8(rtwdev, R_AX_DBI_FLAG + 2, B_AX_DBI_WFLAG >> 16); + + ret = read_poll_timeout_atomic(rtw89_read8, flag, !flag, 10, + 10 * RTW89_PCI_WR_RETRY_CNT, false, + rtwdev, R_AX_DBI_FLAG + 2); + if (ret) + rtw89_err(rtwdev, "failed to write DBI register, addr=0x%X\n", + addr); + + return ret; +} + +static int rtw89_dbi_read8(struct rtw89_dev *rtwdev, u16 addr, u8 *value) +{ + u16 read_addr = addr & B_AX_DBI_ADDR_MSK; + u8 flag; + int ret; + + rtw89_write16(rtwdev, R_AX_DBI_FLAG, read_addr); + rtw89_write8(rtwdev, R_AX_DBI_FLAG + 2, B_AX_DBI_RFLAG >> 16); + + ret = read_poll_timeout_atomic(rtw89_read8, flag, !flag, 10, + 10 * RTW89_PCI_WR_RETRY_CNT, false, + rtwdev, R_AX_DBI_FLAG + 2); + if (ret) { + rtw89_err(rtwdev, "failed to read DBI register, addr=0x%X\n", + addr); + return ret; + } + + read_addr = R_AX_DBI_RDATA + (addr & 3); + *value = rtw89_read8(rtwdev, read_addr); + + return 0; +} + static int rtw89_pci_write_config_byte(struct rtw89_dev *rtwdev, u16 addr, u8 data) { struct rtw89_pci *rtwpci = (struct rtw89_pci *)rtwdev->priv; + enum rtw89_core_chip_id chip_id = rtwdev->chip->chip_id; struct pci_dev *pdev = rtwpci->pdev; + int ret; + + ret = pci_write_config_byte(pdev, addr, data); + if (!ret) + return 0; - return pci_write_config_byte(pdev, addr, data); + if (chip_id == RTL8852A || chip_id == RTL8852B || chip_id == RTL8851B) + ret = rtw89_dbi_write8(rtwdev, addr, data); + + return ret; } static int rtw89_pci_read_config_byte(struct rtw89_dev *rtwdev, u16 addr, u8 *value) { struct rtw89_pci *rtwpci = (struct rtw89_pci *)rtwdev->priv; + enum rtw89_core_chip_id chip_id = rtwdev->chip->chip_id; struct pci_dev *pdev = rtwpci->pdev; + int ret; - return pci_read_config_byte(pdev, addr, value); + ret = pci_read_config_byte(pdev, addr, value); + if (!ret) + return 0; + + if (chip_id == RTL8852A || chip_id == RTL8852B || chip_id == RTL8851B) + ret = rtw89_dbi_read8(rtwdev, addr, value); + + return ret; } static int rtw89_pci_config_byte_set(struct rtw89_dev *rtwdev, u16 addr, diff --git a/drivers/net/wireless/realtek/rtw89/pci.h b/drivers/net/wireless/realtek/rtw89/pci.h index 4259b79b1..119c0608b 100644 --- a/drivers/net/wireless/realtek/rtw89/pci.h +++ b/drivers/net/wireless/realtek/rtw89/pci.h @@ -42,6 +42,7 @@ #define B_AX_DBI_WFLAG BIT(16) #define B_AX_DBI_WREN_MSK GENMASK(15, 12) #define B_AX_DBI_ADDR_MSK GENMASK(11, 2) +#define B_AX_DBI_2LSB GENMASK(1, 0) #define R_AX_DBI_WDATA 0x1094 #define R_AX_DBI_RDATA 0x1098 -- 2.49.0
