[PATCH 6.0 487/862] tty: xilinx_uartps: Check clk_enable return value

From: Greg Kroah-Hartman
Date: Wed Oct 19 2022 - 05:22:35 EST


From: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>

[ Upstream commit 957e8c047bf25bd24271ab049f06dc47f382973f ]

If clocks are not enabled the register access may hang the system.
Check for the clock enable return value and bail out if not enabled.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220729114748.18332-2-shubhrajyoti.datta@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Stable-dep-of: b8a6c3b3d465 ("tty: xilinx_uartps: Fix the ignore_status")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/tty/serial/xilinx_uartps.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index 9e01fe6c0ab8..51fd09e14eda 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -1329,12 +1329,20 @@ static int cdns_uart_resume(struct device *device)
unsigned long flags;
u32 ctrl_reg;
int may_wake;
+ int ret;

may_wake = device_may_wakeup(device);

if (console_suspend_enabled && uart_console(port) && !may_wake) {
- clk_enable(cdns_uart->pclk);
- clk_enable(cdns_uart->uartclk);
+ ret = clk_enable(cdns_uart->pclk);
+ if (ret)
+ return ret;
+
+ ret = clk_enable(cdns_uart->uartclk);
+ if (ret) {
+ clk_disable(cdns_uart->pclk);
+ return ret;
+ }

spin_lock_irqsave(&port->lock, flags);

--
2.35.1