Commit f3be347e authored by Christian A. Ehrhardt's avatar Christian A. Ehrhardt Committed by Greg Kroah-Hartman
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usb: ucsi_acpi: Quirk to ack a connector change ack cmd 



The PPM on some Dell laptops seems to expect that the ACK_CC_CI
command to clear the connector change notification is in turn
followed by another ACK_CC_CI to acknowledge the ACK_CC_CI command
itself. This is in violation of the UCSI spec that states:

    "The only notification that is not acknowledged by the OPM is
     the command completion notification for the ACK_CC_CI or the
     PPM_RESET command."

Add a quirk to send this ack anyway.
Apply the quirk to all Dell systems.

On the first command that acks a connector change send a dummy
command to determine if it runs into a timeout. Only activate
the quirk if it does. This ensure that we do not break Dell
systems that do not need the quirk.

Signed-off-by: default avatar"Christian A. Ehrhardt" <lk@c--e.de>
Reviewed-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20240121204123.275441-4-lk@c--e.de


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 2840143e

drivers/usb/typec/ucsi/ucsi_acpi.c

+68 −3
Original line number Diff line number Diff line
@@ -25,6 +25,8 @@ struct ucsi_acpi { 
	unsigned long flags;

	guid_t guid;

	u64 cmd;

	bool dell_quirk_probed;

	bool dell_quirk_active;

};



static int ucsi_acpi_dsm(struct ucsi_acpi *ua, int func)
@@ -126,12 +128,73 @@ static const struct ucsi_operations ucsi_zenbook_ops = { 
	.async_write = ucsi_acpi_async_write

};



static const struct dmi_system_id zenbook_dmi_id[] = {

/*

 * Some Dell laptops expect that an ACK command with the

 * UCSI_ACK_CONNECTOR_CHANGE bit set is followed by a (separate)

 * ACK command that only has the UCSI_ACK_COMMAND_COMPLETE bit set.

 * If this is not done events are not delivered to OSPM and

 * subsequent commands will timeout.

 */

static int

ucsi_dell_sync_write(struct ucsi *ucsi, unsigned int offset,

		     const void *val, size_t val_len)

{

	struct ucsi_acpi *ua = ucsi_get_drvdata(ucsi);

	u64 cmd = *(u64 *)val, ack = 0;

	int ret;



	if (UCSI_COMMAND(cmd) == UCSI_ACK_CC_CI &&

	    cmd & UCSI_ACK_CONNECTOR_CHANGE)

		ack = UCSI_ACK_CC_CI | UCSI_ACK_COMMAND_COMPLETE;



	ret = ucsi_acpi_sync_write(ucsi, offset, val, val_len);

	if (ret != 0)

		return ret;

	if (ack == 0)

		return ret;



	if (!ua->dell_quirk_probed) {

		ua->dell_quirk_probed = true;



		cmd = UCSI_GET_CAPABILITY;

		ret = ucsi_acpi_sync_write(ucsi, UCSI_CONTROL, &cmd,

					   sizeof(cmd));

		if (ret == 0)

			return ucsi_acpi_sync_write(ucsi, UCSI_CONTROL,

						    &ack, sizeof(ack));

		if (ret != -ETIMEDOUT)

			return ret;



		ua->dell_quirk_active = true;

		dev_err(ua->dev, "Firmware bug: Additional ACK required after ACKing a connector change.\n");

		dev_err(ua->dev, "Firmware bug: Enabling workaround\n");

	}



	if (!ua->dell_quirk_active)

		return ret;



	return ucsi_acpi_sync_write(ucsi, UCSI_CONTROL, &ack, sizeof(ack));

}



static const struct ucsi_operations ucsi_dell_ops = {

	.read = ucsi_acpi_read,

	.sync_write = ucsi_dell_sync_write,

	.async_write = ucsi_acpi_async_write

};



static const struct dmi_system_id ucsi_acpi_quirks[] = {

	{

		.matches = {

			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),

			DMI_MATCH(DMI_PRODUCT_NAME, "ZenBook UX325UA_UM325UA"),

		},

		.driver_data = (void *)&ucsi_zenbook_ops,

	},

	{

		.matches = {

			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),

		},

		.driver_data = (void *)&ucsi_dell_ops,

	},

	{ }

};
@@ -160,6 +223,7 @@ static int ucsi_acpi_probe(struct platform_device *pdev) 
{

	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);

	const struct ucsi_operations *ops = &ucsi_acpi_ops;

	const struct dmi_system_id *id;

	struct ucsi_acpi *ua;

	struct resource *res;

	acpi_status status;
@@ -189,8 +253,9 @@ static int ucsi_acpi_probe(struct platform_device *pdev) 
	init_completion(&ua->complete);

	ua->dev = &pdev->dev;



	if (dmi_check_system(zenbook_dmi_id))

		ops = &ucsi_zenbook_ops;

	id = dmi_first_match(ucsi_acpi_quirks);

	if (id)

		ops = id->driver_data;



	ua->ucsi = ucsi_create(&pdev->dev, ops);

	if (IS_ERR(ua->ucsi))