src: Make implicit fall throughs explicit

Implicit fall throughs are a perpetual source of bugs and Coverity Scan
issues, so let's squash them once and for all. GCC can flag implicit fall
throughs using the -Wimplicit-fallthrough warning, and this should
ensure no more enter the code base. However, many fall throughs are
intentional, and we can use the following comment style to have GCC
suppress the warning.

    switch (x) {
    case 1:
            y += 1;
	    /* fall through */
    case 2:
            y += 2;
	    /* fall through - but this time with an explanation */
    default:
            y += 3;
    }

This patch adds comments for all remaining intentional fall throughs,
and tweaks some existing fall through comments to fit the syntax that
GCC expects.

Change-Id: I1d75637a434a955a58d166ad203e49620d7395ed
Signed-off-by: Jacob Garber <jgarber1@ualberta.ca>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34297
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>

2 files changed, 3 insertions, 4 deletions

diff --git a/src/soc/nvidia/tegra124/sor.c b/src/soc/nvidia/tegra124/sor.c
index 3bc50e813e..52b909e29d 100644
--- a/src/soc/nvidia/tegra124/sor.c
+++ b/src/soc/nvidia/tegra124/sor.c
@@ -237,6 +237,7 @@ static int tegra_dc_sor_power_dplanes(struct tegra_dc_sor_data *sor,
 			/* fall through */
 		case 2:
 			reg_val |= NV_SOR_DP_PADCTL_PD_TXD_1_NO;
+			/* fall through */
 		case 1:
 			reg_val |= NV_SOR_DP_PADCTL_PD_TXD_0_NO;
 			break;
diff --git a/src/soc/rockchip/rk3288/sdram.c b/src/soc/rockchip/rk3288/sdram.c
index 53c594a4b3..74038b078e 100644
--- a/src/soc/rockchip/rk3288/sdram.c
+++ b/src/soc/rockchip/rk3288/sdram.c
@@ -751,10 +751,8 @@ static void move_to_config_state(struct rk3288_ddr_publ_regs *ddr_publ_regs,
 			while ((read32(&ddr_publ_regs->pgsr) & PGSR_DLDONE)
 				!= PGSR_DLDONE)
 				;
-			/* if at low power state,need wakeup first,
-			 * and then enter the config
-			 * so here no break.
-			 */
+			/* if at low power state, need wakeup first, then enter the config */
+			/* fall through */
 		case ACCESS:
 		case INIT_MEM:
 			write32(&ddr_pctl_regs->sctl, CFG_STATE);