diff options
| author | Lv Zheng <lv.zheng@intel.com> | 2014-10-29 06:33:43 +0300 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2017-10-12 17:28:15 +0300 |
| commit | bfc20d54acae250fde0c8d56fc57fd41ea6dbe99 (patch) | |
| tree | bdaf3adee747c94d6a6b99e4918686d2504da042 /drivers/acpi | |
| parent | 54e0d01bb60532f6ede5dc1ae683a2f5197c3cd2 (diff) | |
| download | linux-bfc20d54acae250fde0c8d56fc57fd41ea6dbe99.tar.xz | |
Revert "ACPI / EC: Add support to disallow QR_EC to be issued before completing previous QR_EC"
commit df9ff91801da603079018f21a9412385b62f0f8e upstream.
It is reported that the following commit breaks Samsung hardware:
Commit: 558e4736f2e1b0e6323adf7a5e4df77ed6cfc1a4.
Subject: ACPI / EC: Add support to disallow QR_EC to be issued before
completing previous QR_EC
Which means the Samsung behavior conflicts with the Acer behavior.
1. Samsung may behave like:
[ +event 1 ] SCI_EVT set
[ +event 2 ] SCI_EVT set
write QR_EC
read event
[ -event 1 ] SCI_EVT clear
Without the above commit, Samsung can work:
[ +event 1 ] SCI_EVT set
[ +event 2 ] SCI_EVT set
write QR_EC
CAN prepare next QR_EC as SCI_EVT=1
read event
[ -event 1 ] SCI_EVT clear
write QR_EC
read event
[ -event 2 ] SCI_EVT clear
With the above commit, Samsung cannot work:
[ +event 1 ] SCI_EVT set
[ +event 2 ] SCI_EVT set
write QR_EC
read event
[ -event 1 ] SCI_EVT clear
CANNOT prepare next QR_EC as SCI_EVT=0
2. Acer may behave like:
[ +event 1 ] SCI_EVT set
[ +event 2 ]
write QR_EC
read event
[ -event 1 ] SCI_EVT clear
[ +event 2 ] SCI_EVT set
Without the above commit, Acer cannot work when there is only 1 event:
[ +event 1 ] SCI_EVT set
write QR_EC
can prepared next QR_EC as SCI_EVT=1
read event
[ -event 1 ] SCI_EVT clear
CANNOT write QR_EC as SCI_EVT=0
With the above commit, Acer can work:
[ +event 1 ] SCI_EVT set
[ +event 2 ]
write QR_EC
read event
[ -event 1 ] SCI_EVT set
can prepare next QR_EC because SCI_EVT=0
CAN write QR_EC as SCI_EVT=1
Since Acer can also work with only the following commit applied:
Commit: 3afcf2ece453e1a8c2c6de19cdf06da3772a1b08
Subject: ACPI / EC: Add support to disallow QR_EC to be issued when
SCI_EVT isn't set
commit 558e4736f2e1b0e6323adf7a5e4df77ed6cfc1a4 can be reverted.
Fixes: 558e4736f2e1 (ACPI / EC: Add support to disallow QR_EC to be issued ...)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=44161
Reported-and-tested-by: Ortwin Glück <odi@odi.ch>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/ec.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c index 4b45f55dd6a9..745c6ac2fead 100644 --- a/drivers/acpi/ec.c +++ b/drivers/acpi/ec.c @@ -299,11 +299,11 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, /* following two actions should be kept atomic */ ec->curr = t; start_transaction(ec); + if (ec->curr->command == ACPI_EC_COMMAND_QUERY) + clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags); spin_unlock_irqrestore(&ec->lock, tmp); ret = ec_poll(ec); spin_lock_irqsave(&ec->lock, tmp); - if (ec->curr->command == ACPI_EC_COMMAND_QUERY) - clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags); ec->curr = NULL; spin_unlock_irqrestore(&ec->lock, tmp); return ret; |