On Mon, May 18, 2026 at 08:47:22PM +0530, Arun Menon wrote: > From: Arun Menon <[email protected]> > > The global increase of TPM_BUFSIZE to 8KB is necessary to support > Post-Quantum Cryptography (PQC) payloads. However, applying this increase > to the tpm_tis_i2c driver is unnecessary and wasteful due to physical > transport limitations as pointed out in [1] > > This commit introduces a local buffer limit that is used in the i2c > driver. > > [1] > https://sashiko.dev/#/patchset/20260324071803.324774-1-armenon%40redhat.com?patch=8319 > > Signed-off-by: Arun Menon <[email protected]> > --- > drivers/char/tpm/tpm_tis_i2c.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/char/tpm/tpm_tis_i2c.c b/drivers/char/tpm/tpm_tis_i2c.c > index 6cd07dd34507..db19d459ea1e 100644 > --- a/drivers/char/tpm/tpm_tis_i2c.c > +++ b/drivers/char/tpm/tpm_tis_i2c.c > @@ -54,6 +54,8 @@ > #define TPM_INTF_CAPABILITY_ZERO 0x0FFFF000 > #define TPM_I2C_INTERFACE_CAPABILITY_ZERO 0x80000000 > > +#define TPM_I2C_BUFSIZE 4096 > + > struct tpm_tis_i2c_phy { > struct tpm_tis_data priv; > struct i2c_client *i2c_client; > @@ -232,7 +234,7 @@ static int tpm_tis_i2c_write_bytes(struct tpm_tis_data > *data, u32 addr, u16 len, > int ret; > u16 wrote = 0; > > - if (len > TPM_BUFSIZE - 1) > + if (len > TPM_I2C_BUFSIZE - 1) > return -EIO; > > phy->io_buf[0] = reg; > @@ -339,7 +341,7 @@ static int tpm_tis_i2c_probe(struct i2c_client *dev) > if (!phy) > return -ENOMEM; > > - phy->io_buf = devm_kzalloc(&dev->dev, TPM_BUFSIZE, GFP_KERNEL); > + phy->io_buf = devm_kzalloc(&dev->dev, TPM_I2C_BUFSIZE, GFP_KERNEL); > if (!phy->io_buf) > return -ENOMEM; > > -- > 2.54.0 >
Reviewed-by: Jarkko Sakkinen <[email protected]> BR, Jarkko
