From 83e7e5d89f04d1c417492940f7922bc8416a8cc4 Mon Sep 17 00:00:00 2001 From: Alexander Sverdlin Date: Wed, 24 May 2023 17:40:40 +0200 Subject: [PATCH] tpm: tis_i2c: Limit write bursts to I2C_SMBUS_BLOCK_MAX (32) bytes Underlying I2C bus drivers not always support longer transfers and imx-lpi2c for instance doesn't. The fix is symmetric to previous patch which fixed the read direction. Cc: stable@vger.kernel.org # v5.20+ Fixes: bbc23a07b072 ("tpm: Add tpm_tis_i2c backend for tpm_tis_core") Tested-by: Michael Haener Signed-off-by: Alexander Sverdlin Reviewed-by: Jarkko Sakkinen Reviewed-by: Jerry Snitselaar Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm_tis_i2c.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_i2c.c b/drivers/char/tpm/tpm_tis_i2c.c index 106fd20d94e4..82fda488e98b 100644 --- a/drivers/char/tpm/tpm_tis_i2c.c +++ b/drivers/char/tpm/tpm_tis_i2c.c @@ -230,19 +230,27 @@ static int tpm_tis_i2c_write_bytes(struct tpm_tis_data *data, u32 addr, u16 len, struct i2c_msg msg = { .addr = phy->i2c_client->addr }; u8 reg = tpm_tis_i2c_address_to_register(addr); int ret; + u16 wrote = 0; if (len > TPM_BUFSIZE - 1) return -EIO; - /* write register and data in one go */ phy->io_buf[0] = reg; - memcpy(phy->io_buf + sizeof(reg), value, len); - - msg.len = sizeof(reg) + len; msg.buf = phy->io_buf; - ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg); - if (ret < 0) - return ret; + while (wrote < len) { + /* write register and data in one go */ + msg.len = sizeof(reg) + len - wrote; + if (msg.len > I2C_SMBUS_BLOCK_MAX) + msg.len = I2C_SMBUS_BLOCK_MAX; + + memcpy(phy->io_buf + sizeof(reg), value + wrote, + msg.len - sizeof(reg)); + + ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg); + if (ret < 0) + return ret; + wrote += msg.len - sizeof(reg); + } return 0; }