6.8-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 6aaceb7d9cd00f3e065dc4b054ecfe52c5253b03 upstream.
Some DELL systems don't like UCSI_ACK_CC_CI commands with the UCSI_ACK_CONNECTOR_CHANGE but not the UCSI_ACK_COMMAND_COMPLETE bit set. The current quirk still leaves room for races because it requires two consecutive ACK commands to be sent.
Refactor and significantly simplify the quirk to fix this: Send a dummy command and bundle the connector change ack with the command completion ack in a single UCSI_ACK_CC_CI command. This removes the need to probe for the quirk.
While there define flag bits for struct ucsi_acpi->flags in ucsi_acpi.c and don't re-use definitions from ucsi.h for struct ucsi->flags.
Fixes: f3be347ea42d ("usb: ucsi_acpi: Quirk to ack a connector change ack cmd") Cc: stable@vger.kernel.org Signed-off-by: Christian A. Ehrhardt lk@c--e.de Reviewed-by: Heikki Krogerus heikki.krogerus@linux.intel.com Tested-by: Neil Armstrong neil.armstrong@linaro.org # on SM8550-QRD Link: https://lore.kernel.org/r/20240320073927.1641788-5-lk@c--e.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/typec/ucsi/ucsi_acpi.c | 71 ++++++++++++++++--------------------- 1 file changed, 31 insertions(+), 40 deletions(-)
--- a/drivers/usb/typec/ucsi/ucsi_acpi.c +++ b/drivers/usb/typec/ucsi/ucsi_acpi.c @@ -23,10 +23,11 @@ struct ucsi_acpi { void *base; struct completion complete; unsigned long flags; +#define UCSI_ACPI_SUPPRESS_EVENT 0 +#define UCSI_ACPI_COMMAND_PENDING 1 +#define UCSI_ACPI_ACK_PENDING 2 guid_t guid; u64 cmd; - bool dell_quirk_probed; - bool dell_quirk_active; };
static int ucsi_acpi_dsm(struct ucsi_acpi *ua, int func) @@ -79,9 +80,9 @@ static int ucsi_acpi_sync_write(struct u int ret;
if (ack) - set_bit(ACK_PENDING, &ua->flags); + set_bit(UCSI_ACPI_ACK_PENDING, &ua->flags); else - set_bit(COMMAND_PENDING, &ua->flags); + set_bit(UCSI_ACPI_COMMAND_PENDING, &ua->flags);
ret = ucsi_acpi_async_write(ucsi, offset, val, val_len); if (ret) @@ -92,9 +93,9 @@ static int ucsi_acpi_sync_write(struct u
out_clear_bit: if (ack) - clear_bit(ACK_PENDING, &ua->flags); + clear_bit(UCSI_ACPI_ACK_PENDING, &ua->flags); else - clear_bit(COMMAND_PENDING, &ua->flags); + clear_bit(UCSI_ACPI_COMMAND_PENDING, &ua->flags);
return ret; } @@ -129,51 +130,40 @@ static const struct ucsi_operations ucsi };
/* - * 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. + * Some Dell laptops don't like ACK commands with the + * UCSI_ACK_CONNECTOR_CHANGE but not the UCSI_ACK_COMMAND_COMPLETE + * bit set. To work around this send a dummy command and bundle the + * UCSI_ACK_CONNECTOR_CHANGE with the UCSI_ACK_COMMAND_COMPLETE + * for the dummy command. */ 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; + u64 cmd = *(u64 *)val; + u64 dummycmd = UCSI_GET_CAPABILITY; int ret;
- if (UCSI_COMMAND(cmd) == UCSI_ACK_CC_CI && - cmd & UCSI_ACK_CONNECTOR_CHANGE) - ack = UCSI_ACK_CC_CI | UCSI_ACK_COMMAND_COMPLETE; + if (cmd == (UCSI_ACK_CC_CI | UCSI_ACK_CONNECTOR_CHANGE)) { + cmd |= 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; + /* + * The UCSI core thinks it is sending a connector change ack + * and will accept new connector change events. We don't want + * this to happen for the dummy command as its response will + * still report the very event that the core is trying to clear. + */ + set_bit(UCSI_ACPI_SUPPRESS_EVENT, &ua->flags); + ret = ucsi_acpi_sync_write(ucsi, UCSI_CONTROL, &dummycmd, + sizeof(dummycmd)); + clear_bit(UCSI_ACPI_SUPPRESS_EVENT, &ua->flags);
- 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) + if (ret < 0) 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)); + return ucsi_acpi_sync_write(ucsi, UCSI_CONTROL, &cmd, sizeof(cmd)); }
static const struct ucsi_operations ucsi_dell_ops = { @@ -209,13 +199,14 @@ static void ucsi_acpi_notify(acpi_handle if (ret) return;
- if (UCSI_CCI_CONNECTOR(cci)) + if (UCSI_CCI_CONNECTOR(cci) && + !test_bit(UCSI_ACPI_SUPPRESS_EVENT, &ua->flags)) ucsi_connector_change(ua->ucsi, UCSI_CCI_CONNECTOR(cci));
if (cci & UCSI_CCI_ACK_COMPLETE && test_bit(ACK_PENDING, &ua->flags)) complete(&ua->complete); if (cci & UCSI_CCI_COMMAND_COMPLETE && - test_bit(COMMAND_PENDING, &ua->flags)) + test_bit(UCSI_ACPI_COMMAND_PENDING, &ua->flags)) complete(&ua->complete); }