From 006c66d1d52f1905e6ccfb615cf27235e4e6e745 Mon Sep 17 00:00:00 2001 From: bui duc phuc Date: Thu, 28 May 2026 12:32:04 +0700 Subject: [PATCH] regmap: reject volatile update_bits() in cache-only mode Prevent _regmap_update_bits() from accessing hardware when the register map is in cache-only mode. Unlike regmap_raw_read() and _regmap_read(), the volatile _regmap_update_bits() fast path bypasses the cache_only check. This can result in unexpected hardware accesses while the device is suspended. Return -EBUSY to ensure behavior is consistent with other cache-only access paths. Signed-off-by: bui duc phuc Link: https://patch.msgid.link/20260528053204.46783-1-phucduc.bui@gmail.com Signed-off-by: Mark Brown --- drivers/base/regmap/regmap.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index b2b26f07f4e3..e6e022b02637 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -3257,6 +3257,9 @@ static int _regmap_update_bits(struct regmap *map, unsigned int reg, *change = false; if (regmap_volatile(map, reg) && map->reg_update_bits) { + if (map->cache_only) + return -EBUSY; + reg = regmap_reg_addr(map, reg); ret = map->reg_update_bits(map->bus_context, reg, mask, val); if (ret == 0 && change)