vTPM: Fix Atmel timeout bug.

Some versions of Atmel TPMs provide invalid values for TPM_CAP_PROP_TIS_TIMEOUT query.
Because timeouts are invalid, every other command after tpm_get_timeouts will fail.
It is a known issue and it was fixed recently in linux kernel tpm_tis.c on 2014-07-29.
This patch does not allow timeouts to be less than standard values.
I tested it on a Dell Latitude E5520 and after making the changes I was able to start vtpmmgr-stubdom.

Signed-off-by: Emil Condrea <emilcondrea@gmail.com>
Acked-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>

diff --git a/tpm_tis.c b/tpm_tis.c
index b067cb75249e46f753cee951d2269a10857994f4..d78c4650ff6436c16a82003bef756793c9fc952f 100644 (file)
--- a/tpm_tis.c
+++ b/tpm_tis.c
@@ -33,6 +33,11 @@
 #ifndef min
        #define min( a, b ) ( ((a) < (b)) ? (a) : (b) )
 #endif
+#define ADJUST_TIMEOUTS_TO_STANDARD(initial,standard,timeout_no)                       \
+       if((initial) < (standard)){                                                     \
+               (initial) = (standard);                                                 \
+               printk("Timeout %c was adjusted to standard value.\n",timeout_no);      \
+       }
 
 #define TPM_HEADER_SIZE 10
 
@@ -997,15 +1002,22 @@ int tpm_get_timeouts(struct tpm_chip *chip)
    }
    if (timeout)
       chip->timeout_a = MICROSECS(timeout * scale); /*Convert to msec */
+   ADJUST_TIMEOUTS_TO_STANDARD(chip->timeout_a,MILLISECS(TIS_SHORT_TIMEOUT),'a');
+
    timeout = be32_to_cpu(timeout_cap->b);
    if (timeout)
       chip->timeout_b = MICROSECS(timeout * scale); /*Convert to msec */
+   ADJUST_TIMEOUTS_TO_STANDARD(chip->timeout_b,MILLISECS(TIS_LONG_TIMEOUT),'b');
+
    timeout = be32_to_cpu(timeout_cap->c);
    if (timeout)
       chip->timeout_c = MICROSECS(timeout * scale); /*Convert to msec */
+   ADJUST_TIMEOUTS_TO_STANDARD(chip->timeout_c,MILLISECS(TIS_SHORT_TIMEOUT),'c');
+
    timeout = be32_to_cpu(timeout_cap->d);
    if (timeout)
       chip->timeout_d = MICROSECS(timeout * scale); /*Convert to msec */
+   ADJUST_TIMEOUTS_TO_STANDARD(chip->timeout_d,MILLISECS(TIS_SHORT_TIMEOUT),'d');
 
 duration:
    tpm_cmd.header.in = tpm_getcap_header;