6.6-stable review patch. If anyone has any objections, please let me know.
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From: Jonathan McDowell noodles@meta.com
commit 7146dffa875cd00e7a7f918e1fce79c7593ac1fa upstream.
The change to only use interrupts to handle supported status changes introduced an issue when it is necessary to poll for the status. Rather than checking for the status after sleeping the code now sleeps after the check. This means a correct, but slower, status change on the part of the TPM can be missed, resulting in a spurious timeout error, especially on a more loaded system. Switch back to sleeping *then* checking. An up front check of the status has been done at the start of the function, so this does not cause an additional delay when the status is already what we're looking for.
Cc: stable@vger.kernel.org # v6.4+ Fixes: e87fcf0dc2b4 ("tpm, tpm_tis: Only handle supported interrupts") Signed-off-by: Jonathan McDowell noodles@meta.com Reviewed-by: Michal Suchánek msuchanek@suse.de Reviewed-by: Lino Sanfilippo l.sanfilippo@kunbus.com Reviewed-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/char/tpm/tpm_tis_core.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -114,11 +114,10 @@ again: return 0; /* process status changes without irq support */ do { + usleep_range(priv->timeout_min, priv->timeout_max); status = chip->ops->status(chip); if ((status & mask) == mask) return 0; - usleep_range(priv->timeout_min, - priv->timeout_max); } while (time_before(jiffies, stop)); return -ETIME; }