From 522567362b634015ca85b5460482ee0843feb105 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ma=C3=ADra=20Canal?= Date: Fri, 24 Apr 2026 16:34:52 +0100 Subject: [PATCH] clk: bcm: rpi: Mark VEC clock as CLK_IGNORE_UNUSED MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On Raspberry Pi 3B, the VEC clock is used by the VideoCore firmware display driver, which remains active until the vc4 driver loads and sends NOTIFY_DISPLAY_DONE. If this clock is disabled during boot, a bus lockup happens and the firmware becomes unresponsive, causing a complete system lockup. Mark the VEC clock with CLK_IGNORE_UNUSED so it survives the unused clock disablement and remains available until the vc4 driver takes over display management. Fixes: 672299736af6 ("clk: bcm: rpi: Manage clock rate in prepare/unprepare callbacks") Reported-by: Mark Brown Closes: https://lore.kernel.org/r/5f0bec08-f458-4fba-8bf3-06817a100c4c@sirena.org.uk Signed-off-by: Maíra Canal Link: https://patch.msgid.link/20260401111416.562279-2-mcanal@igalia.com Tested-by: Mark Brown Signed-off-by: Mark Brown Acked-by: Brian Masney # Active contributor to clk Reviewed-by: Stefan Wahren Signed-off-by: Stephen Boyd --- drivers/clk/bcm/clk-raspberrypi.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/clk/bcm/clk-raspberrypi.c b/drivers/clk/bcm/clk-raspberrypi.c index df2d246eb6ef..f1a99de6de4f 100644 --- a/drivers/clk/bcm/clk-raspberrypi.c +++ b/drivers/clk/bcm/clk-raspberrypi.c @@ -160,6 +160,13 @@ raspberrypi_clk_variants[RPI_FIRMWARE_NUM_CLK_ID] = { [RPI_FIRMWARE_VEC_CLK_ID] = { .export = true, .minimize = true, + + /* + * If this clock is disabled during boot, it causes a bus + * lockup in RPi 3B. Therefore, make sure it's left enabled + * during boot. + */ + .flags = CLK_IGNORE_UNUSED, }, [RPI_FIRMWARE_DISP_CLK_ID] = { .export = true,