• Hans de Goede's avatar
    serial: 8250_dw: Revert: Do not reclock if already at correct rate · 7dfae6cb
    Hans de Goede authored
    Commit e5d6bd25 ("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: e5d6bd25 ("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: default avatarHans de Goede <hdegoede@redhat.com>
    Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
    Acked-by: default avatarPeter Collingbourne <pcc@google.com>
    Link: https://lore.kernel.org/r/20240317214123.34482-1-hdegoede@redhat.comSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    7dfae6cb
8250_dw.c 21.1 KB