strcmp does return the difference between two strings not only -1,0,1
consequently
 if (strcmp (a,b) == -1)
might lead to taking the wrong branch

-> compare with <= instead.

This also makes the code/behavior compliant with its comments.
(e.g. if PPI Version is 1.0)

Fixes Coverity complaints:
CID: 741083 Misuse of memcmp-style function
CID: 741084 Misuse of memcmp-style function
CID: 741085 Misuse of memcmp-style function

Cc: sta...@vger.kernel.org
Signed-off-by: Peter Huewe <peterhu...@gmx.de>
---
 drivers/char/tpm/tpm_ppi.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/char/tpm/tpm_ppi.c b/drivers/char/tpm/tpm_ppi.c
index 8e562dc..8b2e05a 100644
--- a/drivers/char/tpm/tpm_ppi.c
+++ b/drivers/char/tpm/tpm_ppi.c
@@ -169,7 +169,7 @@ static ssize_t tpm_store_ppi_request(struct device *dev,
         * is updated with function index from SUBREQ to SUBREQ2 since PPI
         * version 1.1
         */
-       if (strcmp(version, "1.1") == -1)
+       if (strcmp(version, "1.1") <= -1)
                params[2].integer.value = TPM_PPI_FN_SUBREQ;
        else
                params[2].integer.value = TPM_PPI_FN_SUBREQ2;
@@ -179,7 +179,7 @@ static ssize_t tpm_store_ppi_request(struct device *dev,
         * string/package type. For PPI version 1.0 and 1.1, use buffer type
         * for compatibility, and use package type since 1.2 according to spec.
         */
-       if (strcmp(version, "1.2") == -1) {
+       if (strcmp(version, "1.2") <= -1) {
                params[3].type = ACPI_TYPE_BUFFER;
                params[3].buffer.length = sizeof(req);
                sscanf(buf, "%d", &req);
@@ -245,7 +245,7 @@ static ssize_t tpm_show_ppi_transition_action(struct device 
*dev,
         * (e.g. Capella with PPI 1.0) need integer/string/buffer type, so for
         * compatibility, define params[3].type as buffer, if PPI version < 1.2
         */
-       if (strcmp(version, "1.2") == -1) {
+       if (strcmp(version, "1.2") <= -1) {
                params[3].type = ACPI_TYPE_BUFFER;
                params[3].buffer.length =  0;
                params[3].buffer.pointer = NULL;
@@ -387,7 +387,7 @@ static ssize_t show_ppi_operations(char *buf, u32 start, 
u32 end)
        kfree(output.pointer);
        output.length = ACPI_ALLOCATE_BUFFER;
        output.pointer = NULL;
-       if (strcmp(version, "1.2") == -1)
+       if (strcmp(version, "1.2") <= -1)
                return -EPERM;
 
        params[2].integer.value = TPM_PPI_FN_GETOPR;
-- 
1.7.8.6

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