On Wed, 19. Feb 15:20, gregkh@linuxfoundation.org wrote:

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

acpi: typec: ucsi: Introduce a ->poll_cci method

to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

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

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

Oh, the stable tag has been mangled here.. I didn't notice this, sorry. Now Cc'ing the appropriate list.

Could you apply the patch to stables based on Fixes tag then, please? They are 6.12 and 6.13.

Thanks!

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(-)

diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c index fcf499cc9458..0fe1476f4c29 100644 --- 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 *ucsi) 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 *ucsi) 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 *ucsi) /* 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 *dev, const struct ucsi_operations *ops) 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); diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h index 82735eb34f0e..28780acc4af2 100644 --- a/drivers/usb/typec/ucsi/ucsi.h +++ b/drivers/usb/typec/ucsi/ucsi.h @@ -62,6 +62,7 @@ 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

@@ -76,6 +77,7 @@ 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);

diff --git a/drivers/usb/typec/ucsi/ucsi_acpi.c b/drivers/usb/typec/ucsi/ucsi_acpi.c index 5c5515551963..ac1ebb5d9527 100644 --- 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 ucsi *ucsi, u16 *version) 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(struct ucsi *ucsi, u64 command) 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 ucsi *ucsi, u64 command) 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

diff --git a/drivers/usb/typec/ucsi/ucsi_ccg.c b/drivers/usb/typec/ucsi/ucsi_ccg.c index 740171f24ef9..4b1668733a4b 100644 --- a/drivers/usb/typec/ucsi/ucsi_ccg.c +++ b/drivers/usb/typec/ucsi/ucsi_ccg.c @@ -664,6 +664,7 @@ static int ucsi_ccg_sync_control(struct ucsi *ucsi, u64 command) 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,

diff --git a/drivers/usb/typec/ucsi/ucsi_glink.c b/drivers/usb/typec/ucsi/ucsi_glink.c index fed39d458090..8af79101a2fc 100644 --- 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_status(struct ucsi_connector *con) 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,

diff --git a/drivers/usb/typec/ucsi/ucsi_stm32g0.c b/drivers/usb/typec/ucsi/ucsi_stm32g0.c index 6923fad31d79..57ef7d83a412 100644 --- 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_handler(int irq, void *data) 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,

diff --git a/drivers/usb/typec/ucsi/ucsi_yoga_c630.c b/drivers/usb/typec/ucsi/ucsi_yoga_c630.c index 4cae85c0dc12..d33e3f2dd1d8 100644 --- 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(struct ucsi *ucsi, u64 command) static 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,

-- 2.48.1