| Message ID | 20221124064442.28042-1-pkshih@realtek.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 823092a53556ebf8656623d0e857626d30fe1e18 |
| Delegated to: | Kalle Valo |
| Headers | show |
| Series | wifi: rtw88: fix race condition when doing H2C command | expand |
On Thu, Nov 24, 2022 at 02:44:42PM +0800, Ping-Ke Shih wrote: > From: Ji-Pin Jou <neo_jou@realtek.com> > > For SDIO/USB interface, since the tranferring speed is slower than > that in PCIE, it may have race condition when the driver sets down > H2C command to the FW. > > In the function rtw_fw_send_h2c_command, before the patch, box_reg > is written first, then box_ex_reg is written. FW starts to work and > fetch the value of box_ex_reg, when the most significant byte of > box_reg(4 bytes) is written. Meanwhile, for SDIO/USB interface, > since the transferring speed is slow, the driver is still in writing > the new value of box_ex_reg through the bus, and FW may get the > wrong value of box_ex_reg at the moment. > > To prevent the above driver/FW racing situation, box_ex_reg is > written first then box_reg. Furthermore, it is written in 4 bytes at > a time, instead of written in one byte one by one. It can increase > the speed for SDIO/USB interface. > > Signed-off-by: Ji-Pin Jou <neo_jou@realtek.com> > Signed-off-by: Ping-Ke Shih <pkshih@realtek.com> This solves the issue with the RTW88 USB patch set reported here: https://lore.kernel.org/linux-wireless/20221122145527.GA29978@pengutronix.de/ Tested-by: Sascha Hauer <s.hauer@pengutronix.de> Sascha > --- > drivers/net/wireless/realtek/rtw88/fw.c | 8 +++----- > drivers/net/wireless/realtek/rtw88/fw.h | 5 +++++ > 2 files changed, 8 insertions(+), 5 deletions(-) > > diff --git a/drivers/net/wireless/realtek/rtw88/fw.c b/drivers/net/wireless/realtek/rtw88/fw.c > index 0b5f903c0f366..b290811d75e1c 100644 > --- a/drivers/net/wireless/realtek/rtw88/fw.c > +++ b/drivers/net/wireless/realtek/rtw88/fw.c > @@ -311,10 +311,10 @@ EXPORT_SYMBOL(rtw_fw_c2h_cmd_isr); > static void rtw_fw_send_h2c_command(struct rtw_dev *rtwdev, > u8 *h2c) > { > + struct rtw_h2c_cmd *h2c_cmd = (struct rtw_h2c_cmd *)h2c; > u8 box; > u8 box_state; > u32 box_reg, box_ex_reg; > - int idx; > int ret; > > rtw_dbg(rtwdev, RTW_DBG_FW, > @@ -356,10 +356,8 @@ static void rtw_fw_send_h2c_command(struct rtw_dev *rtwdev, > goto out; > } > > - for (idx = 0; idx < 4; idx++) > - rtw_write8(rtwdev, box_reg + idx, h2c[idx]); > - for (idx = 0; idx < 4; idx++) > - rtw_write8(rtwdev, box_ex_reg + idx, h2c[idx + 4]); > + rtw_write32(rtwdev, box_ex_reg, le32_to_cpu(h2c_cmd->msg_ext)); > + rtw_write32(rtwdev, box_reg, le32_to_cpu(h2c_cmd->msg)); > > if (++rtwdev->h2c.last_box_num >= 4) > rtwdev->h2c.last_box_num = 0; > diff --git a/drivers/net/wireless/realtek/rtw88/fw.h b/drivers/net/wireless/realtek/rtw88/fw.h > index a5a965803a3cc..bca610dc99ab7 100644 > --- a/drivers/net/wireless/realtek/rtw88/fw.h > +++ b/drivers/net/wireless/realtek/rtw88/fw.h > @@ -81,6 +81,11 @@ struct rtw_c2h_adaptivity { > u8 option; > } __packed; > > +struct rtw_h2c_cmd { > + __le32 msg; > + __le32 msg_ext; > +} __packed; > + > enum rtw_rsvd_packet_type { > RSVD_BEACON, > RSVD_DUMMY, > -- > 2.25.1 >
Ping-Ke Shih <pkshih@realtek.com> wrote: > From: Ji-Pin Jou <neo_jou@realtek.com> > > For SDIO/USB interface, since the tranferring speed is slower than > that in PCIE, it may have race condition when the driver sets down > H2C command to the FW. > > In the function rtw_fw_send_h2c_command, before the patch, box_reg > is written first, then box_ex_reg is written. FW starts to work and > fetch the value of box_ex_reg, when the most significant byte of > box_reg(4 bytes) is written. Meanwhile, for SDIO/USB interface, > since the transferring speed is slow, the driver is still in writing > the new value of box_ex_reg through the bus, and FW may get the > wrong value of box_ex_reg at the moment. > > To prevent the above driver/FW racing situation, box_ex_reg is > written first then box_reg. Furthermore, it is written in 4 bytes at > a time, instead of written in one byte one by one. It can increase > the speed for SDIO/USB interface. > > Signed-off-by: Ji-Pin Jou <neo_jou@realtek.com> > Signed-off-by: Ping-Ke Shih <pkshih@realtek.com> > Tested-by: Sascha Hauer <s.hauer@pengutronix.de> Patch applied to wireless-next.git, thanks. 823092a53556 wifi: rtw88: fix race condition when doing H2C command
diff --git a/drivers/net/wireless/realtek/rtw88/fw.c b/drivers/net/wireless/realtek/rtw88/fw.c index 0b5f903c0f366..b290811d75e1c 100644 --- a/drivers/net/wireless/realtek/rtw88/fw.c +++ b/drivers/net/wireless/realtek/rtw88/fw.c @@ -311,10 +311,10 @@ EXPORT_SYMBOL(rtw_fw_c2h_cmd_isr); static void rtw_fw_send_h2c_command(struct rtw_dev *rtwdev, u8 *h2c) { + struct rtw_h2c_cmd *h2c_cmd = (struct rtw_h2c_cmd *)h2c; u8 box; u8 box_state; u32 box_reg, box_ex_reg; - int idx; int ret; rtw_dbg(rtwdev, RTW_DBG_FW, @@ -356,10 +356,8 @@ static void rtw_fw_send_h2c_command(struct rtw_dev *rtwdev, goto out; } - for (idx = 0; idx < 4; idx++) - rtw_write8(rtwdev, box_reg + idx, h2c[idx]); - for (idx = 0; idx < 4; idx++) - rtw_write8(rtwdev, box_ex_reg + idx, h2c[idx + 4]); + rtw_write32(rtwdev, box_ex_reg, le32_to_cpu(h2c_cmd->msg_ext)); + rtw_write32(rtwdev, box_reg, le32_to_cpu(h2c_cmd->msg)); if (++rtwdev->h2c.last_box_num >= 4) rtwdev->h2c.last_box_num = 0; diff --git a/drivers/net/wireless/realtek/rtw88/fw.h b/drivers/net/wireless/realtek/rtw88/fw.h index a5a965803a3cc..bca610dc99ab7 100644 --- a/drivers/net/wireless/realtek/rtw88/fw.h +++ b/drivers/net/wireless/realtek/rtw88/fw.h @@ -81,6 +81,11 @@ struct rtw_c2h_adaptivity { u8 option; } __packed; +struct rtw_h2c_cmd { + __le32 msg; + __le32 msg_ext; +} __packed; + enum rtw_rsvd_packet_type { RSVD_BEACON, RSVD_DUMMY,