From: Arnd Bergmann Date: Tue, 28 Apr 2020 21:53:54 +0000 (+0200) Subject: drm/bridge: fix stack usage warning on old gcc X-Git-Tag: baikal/mips/sdk5.9~13559^2~13^2~28 X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=71e469f96bd8ac07aa03148d3c8d6de7092f0419;p=kernel.git drm/bridge: fix stack usage warning on old gcc Some older versions of gcc badly optimize code that passes an inline function argument into another function by reference, causing huge stack usage: drivers/gpu/drm/bridge/tc358768.c: In function 'tc358768_bridge_pre_enable': drivers/gpu/drm/bridge/tc358768.c:840:1: error: the frame size of 2256 bytes is larger than 2048 bytes [-Werror=frame-larger-than=] Use a temporary variable as a workaround and add a comment pointing to the gcc bug. Fixes: 84dd3903b80d ("drm/bridge: Add tc358768 driver") Signed-off-by: Arnd Bergmann Reviewed-by: Tomi Valkeinen Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20200428215408.4111675-1-arnd@arndb.de --- diff --git a/drivers/gpu/drm/bridge/tc358768.c b/drivers/gpu/drm/bridge/tc358768.c index 1b39e8d37834a..6650fe4cfc20f 100644 --- a/drivers/gpu/drm/bridge/tc358768.c +++ b/drivers/gpu/drm/bridge/tc358768.c @@ -178,6 +178,8 @@ static int tc358768_clear_error(struct tc358768_priv *priv) static void tc358768_write(struct tc358768_priv *priv, u32 reg, u32 val) { + /* work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 */ + int tmpval = val; size_t count = 2; if (priv->error) @@ -187,7 +189,7 @@ static void tc358768_write(struct tc358768_priv *priv, u32 reg, u32 val) if (reg < 0x100 || reg >= 0x600) count = 1; - priv->error = regmap_bulk_write(priv->regmap, reg, &val, count); + priv->error = regmap_bulk_write(priv->regmap, reg, &tmpval, count); } static void tc358768_read(struct tc358768_priv *priv, u32 reg, u32 *val)