Re: [PATCH v6 3/5] tpm: Convert tpm_find_get_ops() to use tpm_default_chip()

From: Stefan Berger
Date: Tue Jun 26 2018 - 14:36:28 EST


On 06/26/2018 01:23 PM, Stefan Berger wrote:
Convert tpm_find_get_ops() to use tpm_default_chip() in case no chip
is passed in.

Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
---
drivers/char/tpm/tpm-chip.c | 32 +++++++++++++-------------------
1 file changed, 13 insertions(+), 19 deletions(-)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index f551061262c9..b01d34983766 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -124,29 +124,23 @@ EXPORT_SYMBOL_GPL(tpm_default_chip);
*/
struct tpm_chip *tpm_find_get_ops(struct tpm_chip *chip)
{
- struct tpm_chip *res = NULL;
- int chip_num = 0;
- int chip_prev;
-
- mutex_lock(&idr_lock);
+ int rc;

- if (!chip) {
- do {
- chip_prev = chip_num;
- chip = idr_get_next(&dev_nums_idr, &chip_num);
- if (chip && !tpm_try_get_ops(chip)) {
- res = chip;
- break;
- }
- } while (chip_prev != chip_num);
- } else {
+ if (chip) {
if (!tpm_try_get_ops(chip))
- res = chip;
+ return chip;
+ return NULL;
}

- mutex_unlock(&idr_lock);
-
- return res;
+ chip = tpm_default_chip();
+ if (!chip)
+ return NULL;
+ rc = tpm_try_get_ops(chip);
+ /* release additional reference we got from tpm_default_chip() */
+ put_device(&chip->dev);
+ if (!rc)
This should say 'if (rc)'.
+ return NULL;
+ return chip;
}

/**