[PATCH] tpm: add cancel function

This patch provides the logic to check if an operation has been canceled while
waiting for the response to arrive.

Signed-off-by: Kylene Hall <kjhall@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 20 insertions, 12 deletions

diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index b72050c851d2..e7c1dedfe448 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -141,7 +141,7 @@ EXPORT_SYMBOL_GPL(tpm_lpc_bus_init);
 static ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
                             size_t bufsiz)
 {
-        ssize_t len;
+        ssize_t rc;
         u32 count;
         unsigned long stop;
 
@@ -157,10 +157,10 @@ static ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
 
         down(&chip->tpm_mutex);
 
-        if ((len = chip->vendor->send(chip, (u8 *) buf, count)) < 0) {
+        if ((rc = chip->vendor->send(chip, (u8 *) buf, count)) < 0) {
                 dev_err(&chip->pci_dev->dev,
-                        "tpm_transmit: tpm_send: error %zd\n", len);
-                return len;
+                        "tpm_transmit: tpm_send: error %zd\n", rc);
+                goto out;
         }
 
         stop = jiffies + 2 * 60 * HZ;
@@ -170,23 +170,31 @@ static ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
                     chip->vendor->req_complete_val) {
                         goto out_recv;
                 }
-                msleep(TPM_TIMEOUT); /* CHECK */
+
+                if ((status == chip->vendor->req_canceled)) {
+                        dev_err(&chip->pci_dev->dev, "Operation Canceled\n");
+                        rc = -ECANCELED;
+                        goto out;
+                }
+
+                msleep(TPM_TIMEOUT);    /* CHECK */
                 rmb();
         } while (time_before(jiffies, stop));
 
 
         chip->vendor->cancel(chip);
-        dev_err(&chip->pci_dev->dev, "Time expired\n");
-        up(&chip->tpm_mutex);
-        return -EIO;
+        dev_err(&chip->pci_dev->dev, "Operation Timed out\n");
+        rc = -ETIME;
+        goto out;
 
 out_recv:
-        len = chip->vendor->recv(chip, (u8 *) buf, bufsiz);
-        if (len < 0)
+        rc = chip->vendor->recv(chip, (u8 *) buf, bufsiz);
+        if (rc < 0)
                 dev_err(&chip->pci_dev->dev,
-                        "tpm_transmit: tpm_recv: error %zd\n", len);
+                        "tpm_transmit: tpm_recv: error %zd\n", rc);
+out:
         up(&chip->tpm_mutex);
-        return len;
+        return rc;
 }
 
 #define TPM_DIGEST_SIZE 20