From 641511bfcc5e016e259131c53ae041ad3732b342 Mon Sep 17 00:00:00 2001 From: Eddie James Date: Mon, 12 Jun 2023 14:56:52 -0500 Subject: 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 Link: https://lore.kernel.org/r/20230612195657.245125-10-eajames@linux.ibm.com Signed-off-by: Joel Stanley --- drivers/fsi/fsi-core.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'drivers/fsi') 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) { -- cgit v1.2.3