From: Geert Uytterhoeven geert+renesas@glider.be
commit 4194b583c104922c6141d6610bfbce26847959df upstream.
If the DTB for a device with an RZ/A2 SoC lacks a device node for the BSID register, the ID validation code falls back to using a register at address 0x0, which leads to undefined behavior (e.g. reading back a random value).
This could be fixed by letting fam_rza2.reg point to the actual BSID register. However, the hardcoded fallbacks were meant for backwards compatibility with old DTBs only, not for new SoCs. Hence fix this by validating renesas_family.reg before using it.
Fixes: 175f435f44b724e3 ("soc: renesas: identify RZ/A2") Signed-off-by: Geert Uytterhoeven geert+renesas@glider.be Link: https://lore.kernel.org/r/20191016143306.28995-1-geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/soc/renesas/renesas-soc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/soc/renesas/renesas-soc.c +++ b/drivers/soc/renesas/renesas-soc.c @@ -326,7 +326,7 @@ static int __init renesas_soc_init(void) if (np) { chipid = of_iomap(np, 0); of_node_put(np); - } else if (soc->id) { + } else if (soc->id && family->reg) { chipid = ioremap(family->reg, 4); } if (chipid) {