[Skiboot] [PATCH v2 1/2] hw/lpc-uart.c: Fix uninitialised comparison

[ABHISHEK SINGH TOMAR]

From: Abhishek Singh Tomar <abhishek at linux.ibm.com>

The __length variable is not initialized in the Linux
kernel source code but is compared against a value in
uart_opal_write_buffer_space. This results in invalid behavior.

Changes include:

Removing the invalid comparison of __length.
Adding a temporary log statement for testing purposes:
	Inside uart_opal_write_buffer_space: __length=0xf03baaaa050000c0.

opal_console_write_buffer_space is called twice in the
kernel code, but __length remains uninitialized in both
cases. This fix ensures correct behavior by eliminating
the problematic comparison.

This can finally lead to hang/softlock issue in older hardware.

Signed-off-by: Abhishek Singh Tomar <abhishek at linux.ibm.com>
---
 hw/lpc-uart.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/lpc-uart.c b/hw/lpc-uart.c
index c0f9c52ff..a5ffc5f22 100644
--- a/hw/lpc-uart.c
+++ b/hw/lpc-uart.c
@@ -337,7 +337,7 @@ static int64_t uart_opal_write_buffer_space(int64_t term_number,
 	lock(&uart_lock);
 	tx_buf_len = uart_tx_buf_space();
 
-	if ((tx_buf_len < be64_to_cpu(*__length)) && uart_timed_out(1000))
+	if (uart_timed_out(1000))
 		ret = OPAL_TIMEOUT;
 
 	*__length = cpu_to_be64(tx_buf_len);
-- 
2.48.1