Merge branch 'tpmdd-next-v3.6' of git://github.com/shpedoikal/linux into for-linus
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index b429f1e..93211df 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -1182,17 +1182,20 @@
size_t size, loff_t *off)
{
struct tpm_chip *chip = file->private_data;
- size_t in_size = size, out_size;
+ size_t in_size = size;
+ ssize_t out_size;
/* cannot perform a write until the read has cleared
- either via tpm_read or a user_read_timer timeout */
- while (atomic_read(&chip->data_pending) != 0)
- msleep(TPM_TIMEOUT);
-
- mutex_lock(&chip->buffer_mutex);
+ either via tpm_read or a user_read_timer timeout.
+ This also prevents splitted buffered writes from blocking here.
+ */
+ if (atomic_read(&chip->data_pending) != 0)
+ return -EBUSY;
if (in_size > TPM_BUFSIZE)
- in_size = TPM_BUFSIZE;
+ return -E2BIG;
+
+ mutex_lock(&chip->buffer_mutex);
if (copy_from_user
(chip->data_buffer, (void __user *) buf, in_size)) {
@@ -1202,6 +1205,10 @@
/* atomic tpm command send and result receive */
out_size = tpm_transmit(chip, chip->data_buffer, TPM_BUFSIZE);
+ if (out_size < 0) {
+ mutex_unlock(&chip->buffer_mutex);
+ return out_size;
+ }
atomic_set(&chip->data_pending, out_size);
mutex_unlock(&chip->buffer_mutex);
