[PATCH net v1 5/6] net: dsa: microchip: ksz8863_smi: fix bulk access

From: Oleksij Rempel
Date: Wed Mar 22 2023 - 10:31:58 EST


Current regmap bulk access is broken, resulting to wrong reads/writes
if ksz_read64/ksz_write64 functions are used.
Mostly this issue was visible by using ksz8_fdb_dump(), which returned
corrupt MAC address.

The reason is that regmap was configured to have max_raw_read/write,
even if ksz8863_mdio_read/write functions are able to handle unlimited
read/write accesses. On ksz_read64 function we are using multiple 32bit
accesses by incrementing each access by 1 instead of 4. Resulting buffer
had 01234567.12345678 instead of 01234567.89abcdef.

We have multiple ways to fix it:
- enable 4 byte alignment for 32bit accesses. Since the HW do not have
this requirement. It will break driver.
- disable max_raw_* limit.

This patch is removing max_raw_* limit for regmap accesses in ksz8863_smi.

Fixes: 60a364760002 ("net: dsa: microchip: Add Microchip KSZ8863 SMI based driver support")
Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
---
drivers/net/dsa/microchip/ksz8863_smi.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz8863_smi.c b/drivers/net/dsa/microchip/ksz8863_smi.c
index 2f4623f3bd85..2516c9db7fec 100644
--- a/drivers/net/dsa/microchip/ksz8863_smi.c
+++ b/drivers/net/dsa/microchip/ksz8863_smi.c
@@ -70,6 +70,7 @@ static int ksz8863_mdio_write(void *ctx, const void *data, size_t count)
tmp, val[i]);
if (ret < 0)
goto out;
+
}

out:
@@ -82,22 +83,16 @@ static const struct regmap_bus regmap_smi[] = {
{
.read = ksz8863_mdio_read,
.write = ksz8863_mdio_write,
- .max_raw_read = 1,
- .max_raw_write = 1,
},
{
.read = ksz8863_mdio_read,
.write = ksz8863_mdio_write,
.val_format_endian_default = REGMAP_ENDIAN_BIG,
- .max_raw_read = 2,
- .max_raw_write = 2,
},
{
.read = ksz8863_mdio_read,
.write = ksz8863_mdio_write,
.val_format_endian_default = REGMAP_ENDIAN_BIG,
- .max_raw_read = 4,
- .max_raw_write = 4,
}
};

@@ -108,7 +103,6 @@ static const struct regmap_config ksz8863_regmap_config[] = {
.pad_bits = 24,
.val_bits = 8,
.cache_type = REGCACHE_NONE,
- .use_single_read = 1,
.lock = ksz_regmap_lock,
.unlock = ksz_regmap_unlock,
},
@@ -118,7 +112,6 @@ static const struct regmap_config ksz8863_regmap_config[] = {
.pad_bits = 24,
.val_bits = 16,
.cache_type = REGCACHE_NONE,
- .use_single_read = 1,
.lock = ksz_regmap_lock,
.unlock = ksz_regmap_unlock,
},
@@ -128,7 +121,6 @@ static const struct regmap_config ksz8863_regmap_config[] = {
.pad_bits = 24,
.val_bits = 32,
.cache_type = REGCACHE_NONE,
- .use_single_read = 1,
.lock = ksz_regmap_lock,
.unlock = ksz_regmap_unlock,
}
--
2.30.2