serial: 8250_dw: Revert: Do not reclock if already at correct rate
authorHans de Goede <hdegoede@redhat.com>
Sun, 17 Mar 2024 21:41:23 +0000 (22:41 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 9 Apr 2024 13:56:16 +0000 (15:56 +0200)
commit7dfae6cbadc1ac99e38ad19fb08810b31ff167be
tree36c1489cf0cbd645b34dce50c2339a715d813996
parent638441bed666619b4275f68bbca9d1cd731a2063
serial: 8250_dw: Revert: Do not reclock if already at correct rate

Commit e5d6bd25f93d ("serial: 8250_dw: Do not reclock if already at
correct rate") breaks the dw UARTs on Intel Bay Trail (BYT) and
Cherry Trail (CHT) SoCs.

Before this change the RTL8732BS Bluetooth HCI which is found
connected over the dw UART on both BYT and CHT boards works properly:

Bluetooth: hci0: RTL: examining hci_ver=06 hci_rev=000b lmp_ver=06 lmp_subver=8723
Bluetooth: hci0: RTL: rom_version status=0 version=1
Bluetooth: hci0: RTL: loading rtl_bt/rtl8723bs_fw.bin
Bluetooth: hci0: RTL: loading rtl_bt/rtl8723bs_config-OBDA8723.bin
Bluetooth: hci0: RTL: cfg_sz 64, total sz 24508
Bluetooth: hci0: RTL: fw version 0x365d462e

where as after this change probing it fails:

Bluetooth: hci0: RTL: examining hci_ver=06 hci_rev=000b lmp_ver=06 lmp_subver=8723
Bluetooth: hci0: RTL: rom_version status=0 version=1
Bluetooth: hci0: RTL: loading rtl_bt/rtl8723bs_fw.bin
Bluetooth: hci0: RTL: loading rtl_bt/rtl8723bs_config-OBDA8723.bin
Bluetooth: hci0: RTL: cfg_sz 64, total sz 24508
Bluetooth: hci0: command 0xfc20 tx timeout
Bluetooth: hci0: RTL: download fw command failed (-110)

Revert the changes to fix this regression.

Fixes: e5d6bd25f93d ("serial: 8250_dw: Do not reclock if already at correct rate")
Cc: stable@vger.kernel.org
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Peter Collingbourne <pcc@google.com>
Link: https://lore.kernel.org/r/20240317214123.34482-1-hdegoede@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/tty/serial/8250/8250_dw.c