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usb: ucsi_acpi: Fix command completion handling

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In case of a spurious or otherwise delayed notification it is
possible that CCI still reports the previous completion. The
UCSI spec is aware of this and provides two completion bits in
CCI, one for normal commands and one for acks. As acks and commands
alternate the notification handler can determine if the completion
bit is from the current command.

The initial UCSI code correctly handled this but the distinction
between the two completion bits was lost with the introduction of
the new API.

To fix this revive the ACK_PENDING bit for ucsi_acpi and only complete
commands if the completion bit matches.

Fixes: f56de278e8 ("usb: typec: ucsi: acpi: Move to the new API")
Cc: stable@vger.kernel.org
Signed-off-by: "Christian A. Ehrhardt" <lk@c--e.de>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20240121204123.275441-3-lk@c--e.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Christian A. Ehrhardt 2024-01-21 21:41:22 +01:00 committed by Greg Kroah-Hartman
parent c9aed03a0a
commit 2840143e39
1 changed files with 13 additions and 4 deletions
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17
drivers/usb/typec/ucsi/ucsi_acpi.c
View File

@ -73,9 +73,13 @@ static int ucsi_acpi_sync_write(struct ucsi *ucsi, unsigned int offset,
const void *val, size_t val_len)
{
struct ucsi_acpi *ua = ucsi_get_drvdata(ucsi);
bool ack = UCSI_COMMAND(*(u64 *)val) == UCSI_ACK_CC_CI;
int ret;
set_bit(COMMAND_PENDING, &ua->flags);
if (ack)
set_bit(ACK_PENDING, &ua->flags);
else
set_bit(COMMAND_PENDING, &ua->flags);
ret = ucsi_acpi_async_write(ucsi, offset, val, val_len);
if (ret)
@ -85,7 +89,10 @@ static int ucsi_acpi_sync_write(struct ucsi *ucsi, unsigned int offset,
ret = -ETIMEDOUT;
out_clear_bit:
clear_bit(COMMAND_PENDING, &ua->flags);
if (ack)
clear_bit(ACK_PENDING, &ua->flags);
else
clear_bit(COMMAND_PENDING, &ua->flags);
return ret;
}
@ -142,8 +149,10 @@ static void ucsi_acpi_notify(acpi_handle handle, u32 event, void *data)
if (UCSI_CCI_CONNECTOR(cci))
ucsi_connector_change(ua->ucsi, UCSI_CCI_CONNECTOR(cci));
if (test_bit(COMMAND_PENDING, &ua->flags) &&
cci & (UCSI_CCI_ACK_COMPLETE | UCSI_CCI_COMMAND_COMPLETE))
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))
complete(&ua->complete);
}