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authorAlexander Sverdlin <alexander.sverdlin@siemens.com>2023-05-24 18:40:40 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-07-23 14:49:31 +0300
commitad249709d2747c127b02d456f058990c0ad3ae6d (patch)
tree798dc687710c8baa0a8e871da81088f92d22770e /drivers/char
parentf5a734a689e80c24671456ee3898dc0d68cfe51a (diff)
downloadlinux-ad249709d2747c127b02d456f058990c0ad3ae6d.tar.xz
tpm: tis_i2c: Limit write bursts to I2C_SMBUS_BLOCK_MAX (32) bytes
commit 83e7e5d89f04d1c417492940f7922bc8416a8cc4 upstream. 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 <michael.haener@siemens.com> Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/tpm/tpm_tis_i2c.c22
1 files changed, 15 insertions, 7 deletions
diff --git a/drivers/char/tpm/tpm_tis_i2c.c b/drivers/char/tpm/tpm_tis_i2c.c
index 8422af2abf88..9586e0857a3e 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;
}