[PATCH 6.18 682/752] MIPS: rb532: Fix MMIO UART resource registration

Sasha Levin
2026-02-28T17:58:18Z

From: Jiaxun Yang <jiaxun.yang@flygoat.com>

[ Upstream commit e93bb4b76cfefb302534246e892c7667491cb8cc ]

Since commit 6e690d54cfa8 ("serial: 8250: fix return error code in
serial8250_request_std_resource()"), registering an 8250 MMIO port
without mapbase no longer works, as the resource range is derived from
mapbase/mapsize.

Populate mapbase and mapsize accordingly. Also drop ugly membase KSEG1
pointer and set UPF_IOREMAP instead, letting the 8250 core perform the
ioremap.

Fixes: 6e690d54cfa8 ("serial: 8250: fix return error code in serial8250_request_std_resource()")
Cc: stable@vger.kernel.org
Reported-by: Waldemar Brodkorb <wbx@openadk.org>
Link: https://lore.kernel.org/linux-mips/aX-d0ShTplHKZT33@waldemar-brodkorb.de/
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/mips/rb532/devices.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/mips/rb532/devices.c b/arch/mips/rb532/devices.c
index b7f6f782d9a13..ffa4d38ca95df 100644
--- a/arch/mips/rb532/devices.c
+++ b/arch/mips/rb532/devices.c
@@ -212,11 +212,12 @@ static struct platform_device rb532_wdt = {
static struct plat_serial8250_port rb532_uart_res[] = {
{
.type = PORT_16550A,
- .membase = (char *)KSEG1ADDR(REGBASE + UART0BASE),
+ .mapbase = REGBASE + UART0BASE,
+ .mapsize = 0x1000,
.irq = UART0_IRQ,
.regshift = 2,
.iotype = UPIO_MEM,
- .flags = UPF_BOOT_AUTOCONF,
+ .flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP,
},
{
.flags = 0,
--
2.51.0