--- /dev/null
+From 976e7e9bdc7719a023a4ecccd2e3daec9ab20a40 Mon Sep 17 00:00:00 2001
+From: "Christian A. Ehrhardt" <lk@c--e.de>
+Date: Mon, 17 Feb 2025 13:54:39 +0300
+Subject: acpi: typec: ucsi: Introduce a ->poll_cci method
+
+From: Christian A. Ehrhardt <lk@c--e.de>
+
+commit 976e7e9bdc7719a023a4ecccd2e3daec9ab20a40 upstream.
+
+For the ACPI backend of UCSI the UCSI "registers" are just a memory copy
+of the register values in an opregion. The ACPI implementation in the
+BIOS ensures that the opregion contents are synced to the embedded
+controller and it ensures that the registers (in particular CCI) are
+synced back to the opregion on notifications. While there is an ACPI call
+that syncs the actual registers to the opregion there is rarely a need to
+do this and on some ACPI implementations it actually breaks in various
+interesting ways.
+
+The only reason to force a sync from the embedded controller is to poll
+CCI while notifications are disabled. Only the ucsi core knows if this
+is the case and guessing based on the current command is suboptimal, i.e.
+leading to the following spurious assertion splat:
+
+WARNING: CPU: 3 PID: 76 at drivers/usb/typec/ucsi/ucsi.c:1388 ucsi_reset_ppm+0x1b4/0x1c0 [typec_ucsi]
+CPU: 3 UID: 0 PID: 76 Comm: kworker/3:0 Not tainted 6.12.11-200.fc41.x86_64 #1
+Hardware name: LENOVO 21D0/LNVNB161216, BIOS J6CN45WW 03/17/2023
+Workqueue: events_long ucsi_init_work [typec_ucsi]
+RIP: 0010:ucsi_reset_ppm+0x1b4/0x1c0 [typec_ucsi]
+Call Trace:
+ <TASK>
+ ucsi_init_work+0x3c/0xac0 [typec_ucsi]
+ process_one_work+0x179/0x330
+ worker_thread+0x252/0x390
+ kthread+0xd2/0x100
+ ret_from_fork+0x34/0x50
+ ret_from_fork_asm+0x1a/0x30
+ </TASK>
+
+Thus introduce a ->poll_cci() method that works like ->read_cci() with an
+additional forced sync and document that this should be used when polling
+with notifications disabled. For all other backends that presumably don't
+have this issue use the same implementation for both methods.
+
+Fixes: fa48d7e81624 ("usb: typec: ucsi: Do not call ACPI _DSM method for UCSI read operations")
+Cc: stable <stable@kernel.org>
+Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>
+Tested-by: Fedor Pchelkin <boddah8794@gmail.com>
+Signed-off-by: Fedor Pchelkin <boddah8794@gmail.com>
+Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
+Link: https://lore.kernel.org/r/20250217105442.113486-2-boddah8794@gmail.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/usb/typec/ucsi/ucsi.c | 10 +++++-----
+ drivers/usb/typec/ucsi/ucsi.h | 2 ++
+ drivers/usb/typec/ucsi/ucsi_acpi.c | 21 ++++++++++++++-------
+ drivers/usb/typec/ucsi/ucsi_ccg.c | 1 +
+ drivers/usb/typec/ucsi/ucsi_glink.c | 1 +
+ drivers/usb/typec/ucsi/ucsi_stm32g0.c | 1 +
+ drivers/usb/typec/ucsi/ucsi_yoga_c630.c | 1 +
+ 7 files changed, 25 insertions(+), 12 deletions(-)
+
+--- a/drivers/usb/typec/ucsi/ucsi.c
++++ b/drivers/usb/typec/ucsi/ucsi.c
+@@ -1346,7 +1346,7 @@ static int ucsi_reset_ppm(struct ucsi *u
+
+ mutex_lock(&ucsi->ppm_lock);
+
+- ret = ucsi->ops->read_cci(ucsi, &cci);
++ ret = ucsi->ops->poll_cci(ucsi, &cci);
+ if (ret < 0)
+ goto out;
+
+@@ -1364,7 +1364,7 @@ static int ucsi_reset_ppm(struct ucsi *u
+
+ tmo = jiffies + msecs_to_jiffies(UCSI_TIMEOUT_MS);
+ do {
+- ret = ucsi->ops->read_cci(ucsi, &cci);
++ ret = ucsi->ops->poll_cci(ucsi, &cci);
+ if (ret < 0)
+ goto out;
+ if (cci & UCSI_CCI_COMMAND_COMPLETE)
+@@ -1393,7 +1393,7 @@ static int ucsi_reset_ppm(struct ucsi *u
+ /* Give the PPM time to process a reset before reading CCI */
+ msleep(20);
+
+- ret = ucsi->ops->read_cci(ucsi, &cci);
++ ret = ucsi->ops->poll_cci(ucsi, &cci);
+ if (ret)
+ goto out;
+
+@@ -1929,8 +1929,8 @@ struct ucsi *ucsi_create(struct device *
+ struct ucsi *ucsi;
+
+ if (!ops ||
+- !ops->read_version || !ops->read_cci || !ops->read_message_in ||
+- !ops->sync_control || !ops->async_control)
++ !ops->read_version || !ops->read_cci || !ops->poll_cci ||
++ !ops->read_message_in || !ops->sync_control || !ops->async_control)
+ return ERR_PTR(-EINVAL);
+
+ ucsi = kzalloc(sizeof(*ucsi), GFP_KERNEL);
+--- a/drivers/usb/typec/ucsi/ucsi.h
++++ b/drivers/usb/typec/ucsi/ucsi.h
+@@ -61,6 +61,7 @@ struct dentry;
+ * struct ucsi_operations - UCSI I/O operations
+ * @read_version: Read implemented UCSI version
+ * @read_cci: Read CCI register
++ * @poll_cci: Read CCI register while polling with notifications disabled
+ * @read_message_in: Read message data from UCSI
+ * @sync_control: Blocking control operation
+ * @async_control: Non-blocking control operation
+@@ -75,6 +76,7 @@ struct dentry;
+ struct ucsi_operations {
+ int (*read_version)(struct ucsi *ucsi, u16 *version);
+ int (*read_cci)(struct ucsi *ucsi, u32 *cci);
++ int (*poll_cci)(struct ucsi *ucsi, u32 *cci);
+ int (*read_message_in)(struct ucsi *ucsi, void *val, size_t val_len);
+ int (*sync_control)(struct ucsi *ucsi, u64 command);
+ int (*async_control)(struct ucsi *ucsi, u64 command);
+--- a/drivers/usb/typec/ucsi/ucsi_acpi.c
++++ b/drivers/usb/typec/ucsi/ucsi_acpi.c
+@@ -59,19 +59,24 @@ static int ucsi_acpi_read_version(struct
+ static int ucsi_acpi_read_cci(struct ucsi *ucsi, u32 *cci)
+ {
+ struct ucsi_acpi *ua = ucsi_get_drvdata(ucsi);
+- int ret;
+-
+- if (UCSI_COMMAND(ua->cmd) == UCSI_PPM_RESET) {
+- ret = ucsi_acpi_dsm(ua, UCSI_DSM_FUNC_READ);
+- if (ret)
+- return ret;
+- }
+
+ memcpy(cci, ua->base + UCSI_CCI, sizeof(*cci));
+
+ return 0;
+ }
+
++static int ucsi_acpi_poll_cci(struct ucsi *ucsi, u32 *cci)
++{
++ struct ucsi_acpi *ua = ucsi_get_drvdata(ucsi);
++ int ret;
++
++ ret = ucsi_acpi_dsm(ua, UCSI_DSM_FUNC_READ);
++ if (ret)
++ return ret;
++
++ return ucsi_acpi_read_cci(ucsi, cci);
++}
++
+ static int ucsi_acpi_read_message_in(struct ucsi *ucsi, void *val, size_t val_len)
+ {
+ struct ucsi_acpi *ua = ucsi_get_drvdata(ucsi);
+@@ -94,6 +99,7 @@ static int ucsi_acpi_async_control(struc
+ static const struct ucsi_operations ucsi_acpi_ops = {
+ .read_version = ucsi_acpi_read_version,
+ .read_cci = ucsi_acpi_read_cci,
++ .poll_cci = ucsi_acpi_poll_cci,
+ .read_message_in = ucsi_acpi_read_message_in,
+ .sync_control = ucsi_sync_control_common,
+ .async_control = ucsi_acpi_async_control
+@@ -142,6 +148,7 @@ static int ucsi_gram_sync_control(struct
+ static const struct ucsi_operations ucsi_gram_ops = {
+ .read_version = ucsi_acpi_read_version,
+ .read_cci = ucsi_acpi_read_cci,
++ .poll_cci = ucsi_acpi_poll_cci,
+ .read_message_in = ucsi_gram_read_message_in,
+ .sync_control = ucsi_gram_sync_control,
+ .async_control = ucsi_acpi_async_control
+--- a/drivers/usb/typec/ucsi/ucsi_ccg.c
++++ b/drivers/usb/typec/ucsi/ucsi_ccg.c
+@@ -664,6 +664,7 @@ err_put:
+ static const struct ucsi_operations ucsi_ccg_ops = {
+ .read_version = ucsi_ccg_read_version,
+ .read_cci = ucsi_ccg_read_cci,
++ .poll_cci = ucsi_ccg_read_cci,
+ .read_message_in = ucsi_ccg_read_message_in,
+ .sync_control = ucsi_ccg_sync_control,
+ .async_control = ucsi_ccg_async_control,
+--- a/drivers/usb/typec/ucsi/ucsi_glink.c
++++ b/drivers/usb/typec/ucsi/ucsi_glink.c
+@@ -206,6 +206,7 @@ static void pmic_glink_ucsi_connector_st
+ static const struct ucsi_operations pmic_glink_ucsi_ops = {
+ .read_version = pmic_glink_ucsi_read_version,
+ .read_cci = pmic_glink_ucsi_read_cci,
++ .poll_cci = pmic_glink_ucsi_read_cci,
+ .read_message_in = pmic_glink_ucsi_read_message_in,
+ .sync_control = ucsi_sync_control_common,
+ .async_control = pmic_glink_ucsi_async_control,
+--- a/drivers/usb/typec/ucsi/ucsi_stm32g0.c
++++ b/drivers/usb/typec/ucsi/ucsi_stm32g0.c
+@@ -424,6 +424,7 @@ static irqreturn_t ucsi_stm32g0_irq_hand
+ static const struct ucsi_operations ucsi_stm32g0_ops = {
+ .read_version = ucsi_stm32g0_read_version,
+ .read_cci = ucsi_stm32g0_read_cci,
++ .poll_cci = ucsi_stm32g0_read_cci,
+ .read_message_in = ucsi_stm32g0_read_message_in,
+ .sync_control = ucsi_sync_control_common,
+ .async_control = ucsi_stm32g0_async_control,
+--- a/drivers/usb/typec/ucsi/ucsi_yoga_c630.c
++++ b/drivers/usb/typec/ucsi/ucsi_yoga_c630.c
+@@ -74,6 +74,7 @@ static int yoga_c630_ucsi_async_control(
+ const struct ucsi_operations yoga_c630_ucsi_ops = {
+ .read_version = yoga_c630_ucsi_read_version,
+ .read_cci = yoga_c630_ucsi_read_cci,
++ .poll_cci = yoga_c630_ucsi_read_cci,
+ .read_message_in = yoga_c630_ucsi_read_message_in,
+ .sync_control = ucsi_sync_control_common,
+ .async_control = yoga_c630_ucsi_async_control,
projects / thirdparty / kernel / stable-queue.git / commitdiff
