linux-kernel - [PATCH v4 2/6] can: mcp251xfd: utilize gather

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250918064903.241372-3-viken.dadhaniya@oss.qualcomm.com>
Date: Thu, 18 Sep 2025 12:18:59 +0530
From: Viken Dadhaniya <viken.dadhaniya@....qualcomm.com>
To: mkl@...gutronix.de, mani@...nel.org, thomas.kopp@...rochip.com,
        mailhol.vincent@...adoo.fr, robh@...nel.org, krzk+dt@...nel.org,
        conor+dt@...nel.org, linus.walleij@...aro.org, brgl@...ev.pl,
        linux-can@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org
Cc: mukesh.savaliya@....qualcomm.com, anup.kulkarni@....qualcomm.com,
        Gregor Herburger <gregor.herburger@...tq-group.com>,
        Viken Dadhaniya <viken.dadhaniya@....qualcomm.com>
Subject: [PATCH v4 2/6] can: mcp251xfd: utilize gather_write function for all non-CRC writes

From: Gregor Herburger <gregor.herburger@...tq-group.com>

This is a preparation patch to add errata workaround for non crc writes.

Currently for non-crc writes to the chip can go through the
.gather_write, .write or the reg_update_bits callback.

To allow the addition of the errata fix at a single location use
mcp251xfd_regmap_nocrc_gather_write for all non-CRC write instructions,
similar to the crc regmap.

Signed-off-by: Gregor Herburger <gregor.herburger@...tq-group.com>
Tested-by: Viken Dadhaniya <viken.dadhaniya@....qualcomm.com>
Signed-off-by: Viken Dadhaniya <viken.dadhaniya@....qualcomm.com>
---
 .../net/can/spi/mcp251xfd/mcp251xfd-regmap.c  | 25 ++++++++++---------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c
index 8c5be8d1c519..e61cbd209955 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c
@@ -12,14 +12,6 @@
 
 static const struct regmap_config mcp251xfd_regmap_crc;
 
-static int
-mcp251xfd_regmap_nocrc_write(void *context, const void *data, size_t count)
-{
-	struct spi_device *spi = context;
-
-	return spi_write(spi, data, count);
-}
-
 static int
 mcp251xfd_regmap_nocrc_gather_write(void *context,
 				    const void *reg, size_t reg_len,
@@ -47,6 +39,15 @@ mcp251xfd_regmap_nocrc_gather_write(void *context,
 	return spi_sync_transfer(spi, xfer, ARRAY_SIZE(xfer));
 }
 
+static int
+mcp251xfd_regmap_nocrc_write(void *context, const void *data, size_t count)
+{
+	const size_t data_offset = sizeof(__be16);
+
+	return mcp251xfd_regmap_nocrc_gather_write(context, data, data_offset,
+						   data + data_offset, count - data_offset);
+}
+
 static inline bool
 mcp251xfd_update_bits_read_reg(const struct mcp251xfd_priv *priv,
 			       unsigned int reg)
@@ -64,6 +65,7 @@ mcp251xfd_update_bits_read_reg(const struct mcp251xfd_priv *priv,
 	case MCP251XFD_REG_CON:
 	case MCP251XFD_REG_OSC:
 	case MCP251XFD_REG_ECCCON:
+	case MCP251XFD_REG_IOCON:
 		return true;
 	default:
 		mcp251xfd_for_each_rx_ring(priv, ring, n) {
@@ -139,10 +141,9 @@ mcp251xfd_regmap_nocrc_update_bits(void *context, unsigned int reg,
 	tmp_le32 = orig_le32 & ~mask_le32;
 	tmp_le32 |= val_le32 & mask_le32;
 
-	mcp251xfd_spi_cmd_write_nocrc(&buf_tx->cmd, reg + first_byte);
-	memcpy(buf_tx->data, &tmp_le32, len);
-
-	return spi_write(spi, buf_tx, sizeof(buf_tx->cmd) + len);
+	reg += first_byte;
+	mcp251xfd_spi_cmd_write_nocrc(&buf_tx->cmd, reg);
+	return mcp251xfd_regmap_nocrc_gather_write(context, &buf_tx->cmd, 2, &tmp_le32, len);
 }
 
 static int
-- 
2.34.1