Home Home > GIT Browse
summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJavier Martinez Canillas <javierm@redhat.com>2017-12-25 03:22:51 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-03-15 10:56:57 +0100
commit218ce9890104874e6ca1ced0c3f229755eaa1f76 (patch)
treeb0ea7923359d2a02763e7f91de71446e30bcc9e9
parent9e49b027f787e7dfa6f9fefd72923d1e69871e3d (diff)
tpm: only attempt to disable the LPC CLKRUN if is already enabled
commit 6c9f0ce0dffe64da2204f38b0fd90f3ae2a8903c upstream. Commit 5e572cab92f0 ("tpm: Enable CLKRUN protocol for Braswell systems") added logic in the TPM TIS driver to disable the Low Pin Count CLKRUN signal during TPM transactions. Unfortunately this breaks other devices that are attached to the LPC bus like for example PS/2 mouse and keyboards. One flaw with the logic is that it assumes that the CLKRUN is always enabled, and so it unconditionally enables it after a TPM transaction. But it could be that the CLKRUN# signal was already disabled in the LPC bus and so after the driver probes, CLKRUN_EN will remain enabled which may break other devices that are attached to the LPC bus but don't have support for the CLKRUN protocol. Fixes: 5e572cab92f0 ("tpm: Enable CLKRUN protocol for Braswell systems") Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> Tested-by: James Ettle <james@ettle.org.uk> Tested-by: Jeffery Miller <jmiller@neverware.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/char/tpm/tpm_tis_core.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 6e63815990e2..08ae49dee8b1 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -694,7 +694,8 @@ static void tpm_tis_clkrun_enable(struct tpm_chip *chip, bool value)
struct tpm_tis_data *data = dev_get_drvdata(&chip->dev);
u32 clkrun_val;
- if (!IS_ENABLED(CONFIG_X86) || !is_bsw())
+ if (!IS_ENABLED(CONFIG_X86) || !is_bsw() ||
+ !data->ilb_base_addr)
return;
if (value) {
@@ -751,6 +752,7 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
acpi_handle acpi_dev_handle)
{
u32 vendor, intfcaps, intmask;
+ u32 clkrun_val;
u8 rid;
int rc, probe;
struct tpm_chip *chip;
@@ -776,6 +778,13 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
ILB_REMAP_SIZE);
if (!priv->ilb_base_addr)
return -ENOMEM;
+
+ clkrun_val = ioread32(priv->ilb_base_addr + LPC_CNTRL_OFFSET);
+ /* Check if CLKRUN# is already not enabled in the LPC bus */
+ if (!(clkrun_val & LPC_CLKRUN_EN)) {
+ iounmap(priv->ilb_base_addr);
+ priv->ilb_base_addr = NULL;
+ }
}
if (chip->ops->clk_enable != NULL)