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From:   Oleksij Rempel <o.rempel@pengutronix.de>
To:     "David S. Miller" <davem@davemloft.net>,
        Andrew Lunn <andrew@lunn.ch>,
        Eric Dumazet <edumazet@google.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Vladimir Oltean <olteanv@gmail.com>,
        Woojung Huh <woojung.huh@microchip.com>
Cc:     Oleksij Rempel <o.rempel@pengutronix.de>, kernel@pengutronix.de,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        UNGLinuxDriver@microchip.com
Subject: [PATCH net v1 5/6] net: dsa: microchip: ksz8863_smi: fix bulk access
Date:   Wed, 22 Mar 2023 15:31:29 +0100
Message-Id: <20230322143130.1432106-6-o.rempel@pengutronix.de>
In-Reply-To: <20230322143130.1432106-1-o.rempel@pengutronix.de>
References: <20230322143130.1432106-1-o.rempel@pengutronix.de>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

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@pengutronix.de>
---
 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