6.8-stable review patch. If anyone has any objections, please let me know.
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From: Hans de Goede hdegoede@redhat.com
commit 7dfae6cbadc1ac99e38ad19fb08810b31ff167be upstream.
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 | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -357,9 +357,9 @@ static void dw8250_set_termios(struct ua long rate; int ret;
+ clk_disable_unprepare(d->clk); rate = clk_round_rate(d->clk, newrate); - if (rate > 0 && p->uartclk != rate) { - clk_disable_unprepare(d->clk); + if (rate > 0) { /* * Note that any clock-notifer worker will block in * serial8250_update_uartclk() until we are done. @@ -367,8 +367,8 @@ static void dw8250_set_termios(struct ua ret = clk_set_rate(d->clk, newrate); if (!ret) p->uartclk = rate; - clk_prepare_enable(d->clk); } + clk_prepare_enable(d->clk);
dw8250_do_set_termios(p, termios, old); }