mfd: macsmc: Fix key count endianness annotation

SMC firmware returns the value of the #KEY key in big-endian unlike most
other keys. Reading it through apple_smc_read_u32() into a plain u32
and then converting with be32_to_cpu() makes sparse complain:

  drivers/mfd/macsmc.c:462:26: sparse: cast to restricted __be32

Read the raw value into a __be32 using apple_smc_read() instead.

Fixes: e038d985c9 ("mfd: Add Apple Silicon System Management Controller")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202607181046.OANjIoqR-lkp@intel.com/
Signed-off-by: Sven Peter <sven@kernel.org>
Reviewed-by: Janne Grunau <j@jannau.net>
Reviewed-by: Joshua Peisach <jpeisach@ubuntu.com>
Link: https://patch.msgid.link/20260719-b4-macsmc-be32-fix-v1-1-c7b1936307fa@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>
This commit is contained in:
Sven Peter
2026-08-06 14:27:39 +01:00
committed by Lee Jones
parent f5071235a1
commit 0a29aa6052
+5 -3
View File
@@ -410,7 +410,7 @@ static int apple_smc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct apple_smc *smc;
u32 count;
__be32 count;
int ret;
smc = devm_kzalloc(dev, sizeof(*smc), GFP_KERNEL);
@@ -461,8 +461,10 @@ static int apple_smc_probe(struct platform_device *pdev)
dev_set_drvdata(&pdev->dev, smc);
BLOCKING_INIT_NOTIFIER_HEAD(&smc->event_handlers);
ret = apple_smc_read_u32(smc, SMC_KEY(#KEY), &count);
if (ret)
ret = apple_smc_read(smc, SMC_KEY(#KEY), &count, sizeof(count));
if (ret >= 0 && ret != sizeof(count))
ret = -EINVAL;
if (ret < 0)
return dev_err_probe(smc->dev, ret, "Failed to get key count");
smc->key_count = be32_to_cpu(count);