3.16.39-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Andrey Pronin <[email protected]> commit 9754d45e997000ad4021bc4606cc266bb38d876f upstream. Some chips incorrectly support partial reads from TPM_STS register at non-zero offsets. Read the entire 32-bits register instead of making two 8-bit reads to support such devices and reduce the number of bus transactions when obtaining the burstcount from TPM_STS. Fixes: 27084efee0c3 ("tpm: driver for next generation TPM chips") Signed-off-by: Andrey Pronin <[email protected]> Reviewed-by: Jarkko Sakkinen <[email protected]> Signed-off-by: Jarkko Sakkinen <[email protected]> [bwh: Backported to 3.16: - Use raw ioread32() instead of tpm_tis_read32() - Adjust filename, context] Signed-off-by: Ben Hutchings <[email protected]> --- --- a/drivers/char/tpm/tpm_tis.c +++ b/drivers/char/tpm/tpm_tis.c @@ -197,16 +197,15 @@ static int get_burstcount(struct tpm_chi { unsigned long stop; int burstcnt; + u32 value; /* wait for burstcount */ /* which timeout value, spec has 2 answers (c & d) */ stop = jiffies + chip->vendor.timeout_d; do { - burstcnt = ioread8(chip->vendor.iobase + - TPM_STS(chip->vendor.locality) + 1); - burstcnt += ioread8(chip->vendor.iobase + - TPM_STS(chip->vendor.locality) + - 2) << 8; + value = ioread32(chip->vendor.iobase + + TPM_STS(chip->vendor.locality)); + burstcnt = (value >> 8) & 0xFFFF; if (burstcnt) return burstcnt; msleep(TPM_TIMEOUT);
