This is a note to let you know that I've just added the patch titled
serial: 8250_dw: Revert: Do not reclock if already at correct rate
to the 6.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
serial-8250_dw-revert-do-not-reclock-if-already-at-correct-rate.patch
and it can be found in the queue-6.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 7dfae6cbadc1ac99e38ad19fb08810b31ff167be Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@xxxxxxxxxx>
Date: Sun, 17 Mar 2024 22:41:23 +0100
Subject: serial: 8250_dw: Revert: Do not reclock if already at correct rate
From: Hans de Goede <hdegoede@xxxxxxxxxx>
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@xxxxxxxxxxxxxxx
Cc: Peter Collingbourne <pcc@xxxxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Acked-by: Peter Collingbourne <pcc@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240317214123.34482-1-hdegoede@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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);
}
Patches currently in stable-queue which might be from hdegoede@xxxxxxxxxx are
queue-6.8/serial-8250_dw-revert-do-not-reclock-if-already-at-correct-rate.patch
queue-6.8/platform-x86-amd-pmc-extend-framework-13-quirk-to-mo.patch
