diff mbox series

[1/2] tpm: tis_i2c: Limit read bursts to I2C_SMBUS_BLOCK_MAX (32) bytes

Message ID 20230524154040.1204030-1-alexander.sverdlin@siemens.com (mailing list archive)
State New, archived
Headers show
Series [1/2] tpm: tis_i2c: Limit read bursts to I2C_SMBUS_BLOCK_MAX (32) bytes | expand

Commit Message

Sverdlin, Alexander May 24, 2023, 3:40 p.m. UTC 
From: Alexander Sverdlin <alexander.sverdlin@siemens.com>

Underlying I2C bus drivers not always support longer transfers and
imx-lpi2c for instance doesn't. SLB 9673 offers 427-bytes packets.

Visible symptoms are:

tpm tpm0: Error left over data
tpm tpm0: tpm_transmit: tpm_recv: error -5
tpm_tis_i2c: probe of 1-002e failed with error -5

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>
---
 drivers/char/tpm/tpm_tis_i2c.c | 37 ++++++++++++++++++++--------------
 1 file changed, 22 insertions(+), 15 deletions(-)

Comments

Jarkko Sakkinen May 24, 2023, 4:03 p.m. UTC | #1 
On Wed, 2023-05-24 at 17:40 +0200, A. Sverdlin wrote:
> From: Alexander Sverdlin <alexander.sverdlin@siemens.com>
> 
> Underlying I2C bus drivers not always support longer transfers and
> imx-lpi2c for instance doesn't. SLB 9673 offers 427-bytes packets.
> 
> Visible symptoms are:
> 
> tpm tpm0: Error left over data
> tpm tpm0: tpm_transmit: tpm_recv: error -5
> tpm_tis_i2c: probe of 1-002e failed with error -5
> 
> 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>

BR, Jarkko
Jerry Snitselaar May 24, 2023, 6:19 p.m. UTC | #2 
On Wed, May 24, 2023 at 05:40:39PM +0200, A. Sverdlin wrote:
> From: Alexander Sverdlin <alexander.sverdlin@siemens.com>
> 
> Underlying I2C bus drivers not always support longer transfers and
> imx-lpi2c for instance doesn't. SLB 9673 offers 427-bytes packets.
> 
> Visible symptoms are:
> 
> tpm tpm0: Error left over data
> tpm tpm0: tpm_transmit: tpm_recv: error -5
> tpm_tis_i2c: probe of 1-002e failed with error -5
> 
> 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: Jerry Snitselaar <jsnitsel@redhat.com>

> ---
>  drivers/char/tpm/tpm_tis_i2c.c | 37 ++++++++++++++++++++--------------
>  1 file changed, 22 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm_tis_i2c.c b/drivers/char/tpm/tpm_tis_i2c.c
> index c8c34adc14c0..106fd20d94e4 100644
> --- a/drivers/char/tpm/tpm_tis_i2c.c
> +++ b/drivers/char/tpm/tpm_tis_i2c.c
> @@ -189,21 +189,28 @@ static int tpm_tis_i2c_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
>  	int ret;
>  
>  	for (i = 0; i < TPM_RETRY; i++) {
> -		/* write register */
> -		msg.len = sizeof(reg);
> -		msg.buf = &reg;
> -		msg.flags = 0;
> -		ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg);
> -		if (ret < 0)
> -			return ret;
> -
> -		/* read data */
> -		msg.buf = result;
> -		msg.len = len;
> -		msg.flags = I2C_M_RD;
> -		ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg);
> -		if (ret < 0)
> -			return ret;
> +		u16 read = 0;
> +
> +		while (read < len) {
> +			/* write register */
> +			msg.len = sizeof(reg);
> +			msg.buf = &reg;
> +			msg.flags = 0;
> +			ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg);
> +			if (ret < 0)
> +				return ret;
> +
> +			/* read data */
> +			msg.buf = result + read;
> +			msg.len = len - read;
> +			msg.flags = I2C_M_RD;
> +			if (msg.len > I2C_SMBUS_BLOCK_MAX)
> +				msg.len = I2C_SMBUS_BLOCK_MAX;
> +			ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg);
> +			if (ret < 0)
> +				return ret;
> +			read += msg.len;
> +		}
>  
>  		ret = tpm_tis_i2c_sanity_check_read(reg, len, result);
>  		if (ret == 0)
> -- 
> 2.40.1
>
Jarkko Sakkinen June 6, 2023, 9:23 p.m. UTC | #3 
On Wed May 24, 2023 at 6:40 PM EEST, A. Sverdlin wrote:
> From: Alexander Sverdlin <alexander.sverdlin@siemens.com>
>
> Underlying I2C bus drivers not always support longer transfers and
> imx-lpi2c for instance doesn't. SLB 9673 offers 427-bytes packets.
>
> Visible symptoms are:
>
> tpm tpm0: Error left over data
> tpm tpm0: tpm_transmit: tpm_recv: error -5
> tpm_tis_i2c: probe of 1-002e failed with error -5
>

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>
> ---
>  drivers/char/tpm/tpm_tis_i2c.c | 37 ++++++++++++++++++++--------------
>  1 file changed, 22 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm_tis_i2c.c b/drivers/char/tpm/tpm_tis_i2c.c
> index c8c34adc14c0..106fd20d94e4 100644
> --- a/drivers/char/tpm/tpm_tis_i2c.c
> +++ b/drivers/char/tpm/tpm_tis_i2c.c
> @@ -189,21 +189,28 @@ static int tpm_tis_i2c_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
>  	int ret;
>  
>  	for (i = 0; i < TPM_RETRY; i++) {
> -		/* write register */
> -		msg.len = sizeof(reg);
> -		msg.buf = &reg;
> -		msg.flags = 0;
> -		ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg);
> -		if (ret < 0)
> -			return ret;
> -
> -		/* read data */
> -		msg.buf = result;
> -		msg.len = len;
> -		msg.flags = I2C_M_RD;
> -		ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg);
> -		if (ret < 0)
> -			return ret;
> +		u16 read = 0;
> +
> +		while (read < len) {
> +			/* write register */
> +			msg.len = sizeof(reg);
> +			msg.buf = &reg;
> +			msg.flags = 0;
> +			ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg);
> +			if (ret < 0)
> +				return ret;
> +
> +			/* read data */
> +			msg.buf = result + read;
> +			msg.len = len - read;
> +			msg.flags = I2C_M_RD;
> +			if (msg.len > I2C_SMBUS_BLOCK_MAX)
> +				msg.len = I2C_SMBUS_BLOCK_MAX;
> +			ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg);
> +			if (ret < 0)
> +				return ret;
> +			read += msg.len;
> +		}
>  
>  		ret = tpm_tis_i2c_sanity_check_read(reg, len, result);
>  		if (ret == 0)
> -- 
> 2.40.1

Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

BR, Jarkko
diff mbox series

Patch

diff --git a/drivers/char/tpm/tpm_tis_i2c.c b/drivers/char/tpm/tpm_tis_i2c.c
index c8c34adc14c0..106fd20d94e4 100644
--- a/drivers/char/tpm/tpm_tis_i2c.c
+++ b/drivers/char/tpm/tpm_tis_i2c.c
@@ -189,21 +189,28 @@  static int tpm_tis_i2c_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
 	int ret;
 
 	for (i = 0; i < TPM_RETRY; i++) {
-		/* write register */
-		msg.len = sizeof(reg);
-		msg.buf = &reg;
-		msg.flags = 0;
-		ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg);
-		if (ret < 0)
-			return ret;
-
-		/* read data */
-		msg.buf = result;
-		msg.len = len;
-		msg.flags = I2C_M_RD;
-		ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg);
-		if (ret < 0)
-			return ret;
+		u16 read = 0;
+
+		while (read < len) {
+			/* write register */
+			msg.len = sizeof(reg);
+			msg.buf = &reg;
+			msg.flags = 0;
+			ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg);
+			if (ret < 0)
+				return ret;
+
+			/* read data */
+			msg.buf = result + read;
+			msg.len = len - read;
+			msg.flags = I2C_M_RD;
+			if (msg.len > I2C_SMBUS_BLOCK_MAX)
+				msg.len = I2C_SMBUS_BLOCK_MAX;
+			ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg);
+			if (ret < 0)
+				return ret;
+			read += msg.len;
+		}
 
 		ret = tpm_tis_i2c_sanity_check_read(reg, len, result);
 		if (ret == 0)