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ACPI / EC: Remove duplicated ec_wait_ibf0() waiter 

commit 9b80f0f73a upstream.

After we've added the first command byte write into advance_transaction(),
the IBF=0 waiter is duplicated with the command completion waiter
implemented in the ec_poll() because:
   If IBF=1 blocked the first command byte write invoked in the task
   context ec_poll(), it would be kicked off upon IBF=0 interrupt or timed
   out and retried again in the task context.

Remove this seperate and duplicate IBF=0 waiter.  By doing so we can
reduce the overall number of times to access the EC_SC(R) status
register.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891
Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931
Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911
Reported-and-tested-by: Gareth Williams <gareth@garethwilliams.me.uk>
Reported-and-tested-by: Hans de Goede <jwrdegoede@fedoraproject.org>
Reported-by: Barton Xu <tank.xuhan@gmail.com>
Tested-by: Steffen Weber <steffen.weber@gmail.com>
Tested-by: Arthur Chen <axchen@nvidia.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Lv Zheng 2014-06-15 08:41:48 +08:00 committed by Greg Kroah-Hartman
parent 0d501bcbf1
commit 3506335c49
1 changed files with 1 additions and 26 deletions
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27
drivers/acpi/ec.c
View File

@ -281,23 +281,6 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,
return ret;
}
static int ec_check_ibf0(struct acpi_ec *ec)
{
u8 status = acpi_ec_read_status(ec);
return (status & ACPI_EC_FLAG_IBF) == 0;
}
static int ec_wait_ibf0(struct acpi_ec *ec)
{
unsigned long delay = jiffies + msecs_to_jiffies(ec_delay);
/* interrupt wait manually if GPE mode is not active */
while (time_before(jiffies, delay))
if (wait_event_timeout(ec->wait, ec_check_ibf0(ec),
msecs_to_jiffies(1)))
return 0;
return -ETIME;
}
static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
{
int status;
@ -318,12 +301,6 @@ static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
goto unlock;
}
}
if (ec_wait_ibf0(ec)) {
pr_err("input buffer is not empty, "
"aborting transaction\n");
status = -ETIME;
goto end;
}
pr_debug("transaction start (cmd=0x%02x, addr=0x%02x)\n",
t->command, t->wdata ? t->wdata[0] : 0);
/* disable GPE during transaction if storm is detected */
@ -347,7 +324,6 @@ static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t)
set_bit(EC_FLAGS_GPE_STORM, &ec->flags);
}
pr_debug("transaction end\n");
end:
if (ec->global_lock)
acpi_release_global_lock(glk);
unlock:
@ -653,8 +629,7 @@ static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
spin_lock_irqsave(&ec->lock, flags);
advance_transaction(ec);
spin_unlock_irqrestore(&ec->lock, flags);
if (ec_transaction_completed(ec) &&
(acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) {
if (ec_transaction_completed(ec)) {
wake_up(&ec->wait);
ec_check_sci(ec, acpi_ec_read_status(ec));
}