Commit d9cd78ed authored by Dan Carpenter's avatar Dan Carpenter Committed by Sudeep Holla
Browse files

firmware: arm_scpi: Prevent the ternary sign expansion bug 

How the type promotion works in ternary expressions is a bit tricky.
The problem is that scpi_clk_get_val() returns longs, "ret" is a int
which holds a negative error code, and le32_to_cpu() is an unsigned int.
We want the negative error code to be cast to a negative long.  But
because le32_to_cpu() is an u32 then "ret" is type promoted to u32 and
becomes a high positive and then it is promoted to long and it is still
a high positive value.

Fix this by getting rid of the ternary.

Link: https://lore.kernel.org/r/YIE7pdqV/h10tEAK@mwanda


Fixes: 8cb7cf56 ("firmware: add support for ARM System Control and Power Interface(SCPI) protocol")
Reviewed-by: default avatarCristian Marussi <cristian.marussi@arm.com>
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
[sudeep.holla: changed to return 0 as clock rate on error]
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
parent d4f9dddd

drivers/firmware/arm_scpi.c

+3 −1
Original line number Diff line number Diff line
@@ -552,8 +552,10 @@ static unsigned long scpi_clk_get_val(u16 clk_id) 


	ret = scpi_send_message(CMD_GET_CLOCK_VALUE, &le_clk_id,

				sizeof(le_clk_id), &rate, sizeof(rate));

	if (ret)

		return 0;



	return ret ? ret : le32_to_cpu(rate);

	return le32_to_cpu(rate);

}



static int scpi_clk_set_val(u16 clk_id, unsigned long rate)