regmap: sdw-mbq: don't call an unset readable_reg callback

regmap_sdw_mbq_poll_busy() decides whether to poll the Function Busy bit
by calling ctx->readable_reg(), which is a straight copy of
config->readable_reg. That callback is optional: regmap_readable() treats
a NULL ->readable_reg as "every register is readable", and drivers rely on
that. es9356 and tac5xx2-sdw both build an MBQ regmap without one.

Since commit ca1b11b36d ("regmap: sdw-mbq: Allow defers on undeferrable
controls") the poll runs on every -ENODATA, not only for Controls the
driver marked deferrable, so any of those devices answering
COMMAND_IGNORED takes the kernel through a NULL function pointer.

Treat a missing callback the way the rest of regmap does and poll.

Fixes: 5bc493bf0c ("regmap: sdw-mbq: Add support for SDCA deferred controls")
Signed-off-by: Andrey Golovko <andrey.golovko@gmail.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://patch.msgid.link/20260811184500.5312-1-andrey.golovko@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Andrey Golovko 2026-08-11 22:14:35 +03:00 committed by Mark Brown
parent ae7fd6ff4c
commit 00268f9452
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@ -56,7 +56,7 @@ static int regmap_sdw_mbq_poll_busy(struct sdw_slave *slave, unsigned int reg,
reg = SDW_SDCA_CTL(SDW_SDCA_CTL_FUNC(reg), 0,
SDCA_CTL_ENTITY_0_FUNCTION_STATUS, 0);
if (ctx->readable_reg(dev, reg)) {
if (!ctx->readable_reg || ctx->readable_reg(dev, reg)) {
ret = read_poll_timeout(sdw_read_no_pm, val,
val < 0 || !(val & SDCA_CTL_ENTITY_0_FUNCTION_BUSY),
ctx->cfg.retry_us, ctx->cfg.timeout_us,