The modem pm handler in the ams-delta board uses regulator_enable() but does not check for a successful return code:
board-ams-delta.c:521:3: error: ignoring return value of 'regulator_enable', declared with attribute warn_unused_result [-Werror=unused-result] It is not easy to propagate that return code to the callers in uart_configure_port/uart_suspend_port/uart_resume_port, unless we change all UART drivers, and it is unclear what those would do with the return code. Instead, this patch uses a runtime warning to replace the compiletime warning. I have checked that the regulator in question is hardcoded to a fixed-voltage GPIO regulator, and that should never fail to get enabled if I understand the code right. Acked-by: Tony Lindgren <[email protected]> Acked-by: Aaro Koskinen <[email protected]> Link: https://patchwork.kernel.org/patch/8391981/ Signed-off-by: Arnd Bergmann <[email protected]> --- Originally sent in Feb 2016, but it got lost for some reason --- arch/arm/mach-omap1/board-ams-delta.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/arm/mach-omap1/board-ams-delta.c b/arch/arm/mach-omap1/board-ams-delta.c index 6613a6ff5dbc..6cbc69c92913 100644 --- a/arch/arm/mach-omap1/board-ams-delta.c +++ b/arch/arm/mach-omap1/board-ams-delta.c @@ -510,6 +510,7 @@ static void __init ams_delta_init(void) static void modem_pm(struct uart_port *port, unsigned int state, unsigned old) { struct modem_private_data *priv = port->private_data; + int ret; if (IS_ERR(priv->regulator)) return; @@ -518,9 +519,16 @@ static void modem_pm(struct uart_port *port, unsigned int state, unsigned old) return; if (state == 0) - regulator_enable(priv->regulator); + ret = regulator_enable(priv->regulator); else if (old == 0) - regulator_disable(priv->regulator); + ret = regulator_disable(priv->regulator); + else + ret = 0; + + if (ret) + dev_warn(port->dev, + "ams_delta modem_pm: failed to %sable regulator: %d\n", + state ? "dis" : "en", ret); } static struct plat_serial8250_port ams_delta_modem_ports[] = { -- 2.9.0
