Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1502444

[PATCH] tpm, tpm_crb: remove redundant CRB_FL_CRB_START flag

Show all headers | View raw

Because all the existing hardware have HID MSFT0101 we end up always
setting CRB_FL_CRB_START flag as a workaround for 4th Gen Core CPUs.
Even if ACPI start is used, the driver will always issue also CRB start.

This commit makes the invocation of CRB start unconditional.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
 drivers/char/tpm/tpm_crb.c | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index 65040d7..5928ec8 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -72,7 +72,6 @@ enum crb_status {
 
 enum crb_flags {
 	CRB_FL_ACPI_START	= BIT(0),
-	CRB_FL_CRB_START	= BIT(1),
 };
 
 struct crb_priv {
@@ -226,8 +225,11 @@ static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len)
 	/* Make sure that cmd is populated before issuing start. */
 	wmb();
 
-	if (priv->flags & CRB_FL_CRB_START)
-		iowrite32(CRB_START_INVOKE, &priv->cca->start);
+
+	/* At least some of the 4th Gen Core CPUs that report only needing ACPI
+	 * start require also CRB start so we always set it just in case.
+	 */
+	iowrite32(CRB_START_INVOKE, &priv->cca->start);
 
 	if (priv->flags & CRB_FL_ACPI_START)
 		rc = crb_do_acpi_start(chip);
@@ -407,14 +409,6 @@ static int crb_acpi_add(struct acpi_device *device)
 	if (!priv)
 		return -ENOMEM;
 
-	/* The reason for the extra quirk is that the PTT in 4th Gen Core CPUs
-	 * report only ACPI start but in practice seems to require both
-	 * ACPI start and CRB start.
-	 */
-	if (sm == ACPI_TPM2_COMMAND_BUFFER || sm == ACPI_TPM2_MEMORY_MAPPED ||
-	    !strcmp(acpi_device_hid(device), "MSFT0101"))
-		priv->flags |= CRB_FL_CRB_START;
-
 	if (sm == ACPI_TPM2_START_METHOD ||
 	    sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD)
 		priv->flags |= CRB_FL_ACPI_START;
-- 
2.9.3

Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

[PATCH] tpm, tpm_crb: remove redundant CRB_FL_CRB_START flag Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> - 2016-10-17 22:50 +0200
  Re: [PATCH] tpm, tpm_crb: remove redundant CRB_FL_CRB_START flag Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> - 2016-10-18 01:00 +0200
    RE: [tpmdd-devel] [PATCH] tpm, tpm_crb: remove redundant  CRB_FL_CRB_START flag "Winkler, Tomas" <tomas.winkler@intel.com> - 2016-10-19 17:00 +0200
      Re: [tpmdd-devel] [PATCH] tpm, tpm_crb: remove redundant  CRB_FL_CRB_START flag Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> - 2016-10-19 18:10 +0200
        Re: [tpmdd-devel] [PATCH] tpm, tpm_crb: remove redundant  CRB_FL_CRB_START flag Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> - 2016-10-20 16:00 +0200
          Re: [tpmdd-devel] [PATCH] tpm, tpm_crb: remove redundant  CRB_FL_CRB_START flag Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> - 2016-10-20 16:10 +0200
            Re: [tpmdd-devel] [PATCH] tpm, tpm_crb: remove redundant  CRB_FL_CRB_START flag Jason Gunthorpe <jgunthorpe@obsidianresearch.com> - 2016-10-20 22:30 +0200
              Re: [tpmdd-devel] [PATCH] tpm, tpm_crb: remove redundant  CRB_FL_CRB_START flag Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> - 2016-10-21 17:20 +0200
                Re: [tpmdd-devel] [PATCH] tpm, tpm_crb: remove redundant  CRB_FL_CRB_START flag Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> - 2016-10-25 22:40 +0200

csiph-web