Patch "tpm: Keep CLKRUN enabled throughout the duration of transmit_cmd()" has been added to the 4.15-stable tree

This is a note to let you know that I've just added the patch titled

tpm: Keep CLKRUN enabled throughout the duration of transmit_cmd()

to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
tpm-keep-clkrun-enabled-throughout-the-duration-of-transmit_cmd.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Azhar Shaikh <[email protected]>
Date: Fri, 22 Dec 2017 12:13:44 -0800
Subject: tpm: Keep CLKRUN enabled throughout the duration of transmit_cmd()

From: Azhar Shaikh <[email protected]>

commit b3e958ce4c585bf666de249dc794971ebc62d2d3 upstream.

Commit 5e572cab92f0bb5 ("tpm: Enable CLKRUN protocol for Braswell systems") disabled CLKRUN protocol during TPM transactions and re-enabled once the transaction is completed. But there were still some corner cases observed where, reading of TPM header failed for savestate command while going to suspend, which resulted in suspend failure.
To fix this issue keep the CLKRUN protocol disabled for the entire duration of a single TPM command and not disabling and re-enabling again for every TPM transaction. For the other TPM accesses outside TPM command flow, add a higher level of disabling and re-enabling the CLKRUN protocol, instead of doing for every TPM transaction.

---
 drivers/char/tpm/tpm-interface.c |    6 ++
 drivers/char/tpm/tpm_tis.c       |   92 +++------------------------------
 drivers/char/tpm/tpm_tis_core.c  |  108 +++++++++++++++++++++++++++++++++++----
 drivers/char/tpm/tpm_tis_core.h  |    4 +
 include/linux/tpm.h              |    1 
 5 files changed, 119 insertions(+), 92 deletions(-)

@@ -413,6 +413,9 @@ ssize_t tpm_transmit(struct tpm_chip *ch
 	if (chip->dev.parent)
 		pm_runtime_get_sync(chip->dev.parent);
 
+	if (chip->ops->clk_enable != NULL)
+		chip->ops->clk_enable(chip, true);
+
 	/* Store the decision as chip->locality will be changed. */
 	need_locality = chip->locality == -1;
 

@@ -489,6 +492,9 @@ out:
 		chip->locality = -1;
 	}
 out_no_locality:
+	if (chip->ops->clk_enable != NULL)
+		chip->ops->clk_enable(chip, false);
+
 	if (chip->dev.parent)
 		pm_runtime_put_sync(chip->dev.parent);
 

@@ -79,11 +79,14 @@ enum tis_defaults {
 #define	TPM_DID_VID(l)			(0x0F00 | ((l) << 12))
 #define	TPM_RID(l)			(0x0F04 | ((l) << 12))
 
+#define LPC_CNTRL_OFFSET		0x84
+#define LPC_CLKRUN_EN			(1 << 2)
 #define INTEL_LEGACY_BLK_BASE_ADDR	0xFED08000
 #define ILB_REMAP_SIZE			0x100
 
 enum tpm_tis_flags {
 	TPM_TIS_ITPM_WORKAROUND		= BIT(0),
+	TPM_TIS_CLK_ENABLE		= BIT(1),
 };
 
 struct tpm_tis_data {

@@ -93,6 +96,7 @@ struct tpm_tis_data {
 	bool irq_tested;
 	unsigned int flags;
 	void __iomem *ilb_base_addr;
+	u16 clkrun_enabled;
 	wait_queue_head_t int_queue;
 	wait_queue_head_t read_queue;
 	const struct tpm_tis_phy_ops *phy_ops;

@@ -50,6 +50,7 @@ struct tpm_class_ops {
 				unsigned long *timeout_cap);
 	int (*request_locality)(struct tpm_chip *chip, int loc);
 	void (*relinquish_locality)(struct tpm_chip *chip, int loc);
+	void (*clk_enable)(struct tpm_chip *chip, bool value);
 };
 
 #if defined(CONFIG_TCG_TPM) || defined(CONFIG_TCG_TPM_MODULE)

Patches currently in stable-queue which might be from [email protected] are

queue-4.15/tpm_tis-move-ilb_base_addr-to-tpm_tis_data.patch queue-4.15/tpm-keep-clkrun-enabled-throughout-the-duration-of-transmit_cmd.patch