linux-kernel - [PATCH v2 3/4] i2c: designware: Allow SMBus block reads up to 255 bytes in length

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Date:   Wed, 16 Sep 2020 22:22:55 -0700
From:   Sultan Alsawaf <sultan@...neltoast.com>
To:     linux-i2c@...r.kernel.org
Cc:     jikos@...nel.org, aaron.ma@...onical.com, admin@...ma.net,
        andriy.shevchenko@...ux.intel.com, benjamin.tissoires@...hat.com,
        hdegoede@...hat.com, hn.chen@...dahitech.com,
        jarkko.nikula@...ux.intel.com, kai.heng.feng@...onical.com,
        linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
        mika.westerberg@...ux.intel.com, vicamo.yang@...onical.com,
        wsa@...nel.org, Sultan Alsawaf <sultan@...neltoast.com>
Subject: [PATCH v2 3/4] i2c: designware: Allow SMBus block reads up to 255 bytes in length

From: Sultan Alsawaf <sultan@...neltoast.com>

According to the SMBus 3.0 protocol specification, block transfer limits
were increased from 32 bytes to 255 bytes. Remove the obsolete 32-byte
limitation.

Signed-off-by: Sultan Alsawaf <sultan@...neltoast.com>
---
 drivers/i2c/busses/i2c-designware-master.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index 22f28516bca7..5bd64bd17d94 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -433,7 +433,7 @@ i2c_dw_read(struct dw_i2c_dev *dev)
 			regmap_read(dev->map, DW_IC_DATA_CMD, &tmp);
 			if (flags & I2C_M_RECV_LEN) {
 				/* Ensure length byte is a valid value */
-				if (tmp <= I2C_SMBUS_BLOCK_MAX && tmp > 0)
+				if (tmp > 0)
 					len = i2c_dw_recv_len(dev, tmp);
 				else
 					len = i2c_dw_recv_len(dev, len);
-- 
2.28.0