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: f56de278e8ec ("usb: typec: ucsi: acpi: Move to the new API")
Signed-off-by: Christian A. Ehrhardt <[email protected]>
---
NOTES:
- I've seen real issues as a result of this.
- UCSI implementations other than ACPI might need a similar fix.
I can give relevant maintainers a heads up once this is properly
reviewed and integrated.
drivers/usb/typec/ucsi/ucsi_acpi.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/typec/ucsi/ucsi_acpi.c b/drivers/usb/typec/ucsi/ucsi_acpi.c
index 6bbf490ac401..33dac67154d2 100644
--- a/drivers/usb/typec/ucsi/ucsi_acpi.c
+++ b/drivers/usb/typec/ucsi/ucsi_acpi.c
@@ -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);
}
--
2.40.1
On Tue, Jan 16, 2024 at 11:40:40PM +0100, Christian A. Ehrhardt wrote:
> 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: f56de278e8ec ("usb: typec: ucsi: acpi: Move to the new API")
> Signed-off-by: Christian A. Ehrhardt <[email protected]>
> ---
> NOTES:
> - I've seen real issues as a result of this.
> - UCSI implementations other than ACPI might need a similar fix.
> I can give relevant maintainers a heads up once this is properly
> reviewed and integrated.
>
> drivers/usb/typec/ucsi/ucsi_acpi.c | 17 +++++++++++++----
> 1 file changed, 13 insertions(+), 4 deletions(-)
Hi,
This is the friendly patch-bot of Greg Kroah-Hartman. You have sent him
a patch that has triggered this response. He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created. Hopefully you will not take offence and will fix the problem
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If you wish to discuss this problem further, or you have questions about
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thanks,
greg k-h's patch email bot