linux-kernel - [PATCH 2/2] platform/x86/amd: pmc: Add a module parameter to disable workarounds

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Date:   Fri, 20 Jan 2023 13:15:19 -0600
From:   Mario Limonciello <mario.limonciello@....com>
To:     Shyam Sundar S K <Shyam-sundar.S-k@....com>
CC:     <kai.heng.feng@...onical.com>, <xaver.hugl@...il.com>,
        Mario Limonciello <mario.limonciello@....com>,
        Hans de Goede <hdegoede@...hat.com>,
        Mark Gross <markgross@...nel.org>,
        <platform-driver-x86@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
Subject: [PATCH 2/2] platform/x86/amd: pmc: Add a module parameter to disable workarounds

Some users may want to live with the bugs that exist in platform
firmware and have workarounds in AMD PMC driver.

To allow them to bypass these workarounds, introduce a module
parameter.

Signed-off-by: Mario Limonciello <mario.limonciello@....com>
---
 drivers/platform/x86/amd/pmc.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/x86/amd/pmc.c b/drivers/platform/x86/amd/pmc.c
index be1b49824edbd..3cbb01ec10e32 100644
--- a/drivers/platform/x86/amd/pmc.c
+++ b/drivers/platform/x86/amd/pmc.c
@@ -161,6 +161,10 @@ static bool enable_stb;
 module_param(enable_stb, bool, 0644);
 MODULE_PARM_DESC(enable_stb, "Enable the STB debug mechanism");
 
+static bool disable_workarounds;
+module_param(disable_workarounds, bool, 0644);
+MODULE_PARM_DESC(disable_workarounds, "Disable workarounds for platform bugs");
+
 static struct amd_pmc_dev pmc;
 static int amd_pmc_send_cmd(struct amd_pmc_dev *dev, u32 arg, u32 *data, u8 msg, bool ret);
 static int amd_pmc_read_stb(struct amd_pmc_dev *dev, u32 *buf);
@@ -743,8 +747,8 @@ static void amd_pmc_s2idle_prepare(void)
 	/* Reset and Start SMU logging - to monitor the s0i3 stats */
 	amd_pmc_setup_smu_logging(pdev);
 
-	/* Activate CZN specific RTC functionality */
-	if (pdev->cpu_id == AMD_CPU_ID_CZN) {
+	/* Activate CZN specific platform bug workarounds */
+	if (pdev->cpu_id == AMD_CPU_ID_CZN && !disable_workarounds) {
 		rc = amd_pmc_verify_czn_rtc(pdev, &arg);
 		if (rc) {
 			dev_err(pdev->dev, "failed to set RTC: %d\n", rc);
@@ -815,7 +819,7 @@ static int __maybe_unused amd_pmc_suspend_handler(struct device *dev)
 {
 	struct amd_pmc_dev *pdev = dev_get_drvdata(dev);
 
-	if (pdev->cpu_id == AMD_CPU_ID_CZN) {
+	if (pdev->cpu_id == AMD_CPU_ID_CZN && !disable_workarounds) {
 		int rc = amd_pmc_czn_wa_irq1(pdev);
 
 		if (rc) {
-- 
2.34.1