6.13-stable review patch. If anyone has any objections, please let me know.
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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,