Hi James,
The following changes since commit bf5308344527d015ac9a6d2bda4ad4d40fd7d943:
Merge tag 'v3.6-rc7' into next (2012-09-28 13:37:32 +1000)
are available in the git repository at:
git://github.com/shpedoikal/linux.git tpmdd-next-v3.6
for you to fetch changes up to abce9ac292e13da367bbd22c1f7669f988d931ac:
tpm: Propagate error from tpm_transmit to fix a timeout hang (2012-10-10
11:34:31 -0500)
----------------------------------------------------------------
Peter Huewe (1):
tpm: Propagate error from tpm_transmit to fix a timeout hang
drivers/char/tpm/tpm.c | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 6724615..4caef33 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -1182,17 +1182,20 @@ ssize_t tpm_write(struct file *file, const char __user
*buf,
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 @@ ssize_t tpm_write(struct file *file, const char __user
*buf,
/* 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);
--
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