[PATCH 3/7] soc: aspeed: lpc-snoop: Ensure model_data is valid

Andrew Jeffery
2025-04-11T01:09:11Z

of_device_get_match_data() can return NULL, though shouldn't in current
circumstances. Regardless, initialise model_data closer to use so it's
clear we need to test for validity prior to dereferencing.

Fixes: 2dee584bc9e3 ("drivers/misc: (aspeed-lpc-snoop): Add ast2400 to compat")
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
---
drivers/soc/aspeed/aspeed-lpc-snoop.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/soc/aspeed/aspeed-lpc-snoop.c b/drivers/soc/aspeed/aspeed-lpc-snoop.c
index e9d9a8e60a6f062c0b53c9c02e5d73768453998d..28f034b8a3b7226efe20cbe30a7da0c2b49fbd96 100644
--- a/drivers/soc/aspeed/aspeed-lpc-snoop.c
+++ b/drivers/soc/aspeed/aspeed-lpc-snoop.c
@@ -186,10 +186,10 @@ static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop *lpc_snoop,
struct device *dev,
int channel, u16 lpc_port)
{
- int rc = 0;
+ const struct aspeed_lpc_snoop_model_data *model_data;
u32 hicr5_en, snpwadr_mask, snpwadr_shift, hicrb_en;
- const struct aspeed_lpc_snoop_model_data *model_data =
- of_device_get_match_data(dev);
+ int rc = 0;
+

if (lpc_snoop->chan[channel].enabled)
return -EBUSY;
@@ -236,9 +236,10 @@ static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop *lpc_snoop,
regmap_update_bits(lpc_snoop->regmap, HICR5, hicr5_en, hicr5_en);
regmap_update_bits(lpc_snoop->regmap, SNPWADR, snpwadr_mask,
lpc_port << snpwadr_shift);
- if (model_data->has_hicrb_ensnp)
- regmap_update_bits(lpc_snoop->regmap, HICRB,
- hicrb_en, hicrb_en);
+
+ model_data = of_device_get_match_data(dev);
+ if (model_data && model_data->has_hicrb_ensnp)
+ regmap_update_bits(lpc_snoop->regmap, HICRB, hicrb_en, hicrb_en);

lpc_snoop->chan[channel].enabled = true;

--
2.39.5