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fsi: core: Fix legacy minor numbering

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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>
This commit is contained in:
Eddie James 2023-06-12 14:56:52 -05:00 committed by Joel Stanley
parent 02c8fec05b
commit 641511bfcc
1 changed files with 8 additions and 3 deletions
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11
drivers/fsi/fsi-core.c
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@ -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) {