diff options
| author | Eddie James <eajames@us.ibm.com> | 2023-06-12 14:56:52 -0500 |
|---|---|---|
| committer | Joel Stanley <joel@jms.id.au> | 2023-08-09 15:43:28 +0930 |
| commit | 641511bfcc5e016e259131c53ae041ad3732b342 (patch) | |
| tree | 976e222b60653d947317df2b6609bb9235e7595c /drivers/fsi | |
| parent | 02c8fec05bc74d3f50b23c20a54cb6cba3326eef (diff) | |
| download | lwn-641511bfcc5e016e259131c53ae041ad3732b342.tar.gz lwn-641511bfcc5e016e259131c53ae041ad3732b342.zip | |
fsi: core: Fix legacy minor numbering
The legacy minor numbering shifts the chip id too much,
resulting in ids that overlap with regular ids. Since there
are only 2 bits for 4 types, only shift the chip id by 2
to fit the legacy ids in their reserved space.
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20230612195657.245125-10-eajames@linux.ibm.com
Signed-off-by: Joel Stanley <joel@jms.id.au>
Diffstat (limited to 'drivers/fsi')
| -rw-r--r-- | drivers/fsi/fsi-core.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c index 161c45857e1d..8735eddc9745 100644 --- a/drivers/fsi/fsi-core.c +++ b/drivers/fsi/fsi-core.c @@ -913,8 +913,12 @@ static int __fsi_get_new_minor(struct fsi_slave *slave, enum fsi_dev_type type, /* Check if we qualify for legacy numbering */ if (cid >= 0 && cid < 16 && type < 4) { - /* Try reserving the legacy number */ - id = (cid << 4) | type; + /* + * Try reserving the legacy number, which has 0 - 0x3f reserved + * in the ida range. cid goes up to 0xf and type contains two + * bits, so construct the id with the below two bit shift. + */ + id = (cid << 2) | type; id = ida_simple_get(&fsi_minor_ida, id, id + 1, GFP_KERNEL); if (id >= 0) { *out_index = fsi_adjust_index(cid); @@ -949,7 +953,8 @@ int fsi_get_new_minor(struct fsi_device *fdev, enum fsi_dev_type type, int aid = of_alias_get_id(fdev->dev.of_node, fsi_dev_type_names[type]); if (aid >= 0) { - int id = (aid << 4) | type; + /* Use the same scheme as the legacy numbers. */ + int id = (aid << 2) | type; id = ida_simple_get(&fsi_minor_ida, id, id + 1, GFP_KERNEL); if (id >= 0) { |