diff options
authorLan Tianyu <tianyu.lan@intel.com>2013-05-06 03:23:40 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-05-19 11:38:43 -0700
commitdce292e9ad1153354e730824f6d90df2c470784d (patch)
parent1ed59c216723ca3586509ff309fbb987312d922a (diff)
ACPI / EC: Restart transaction even when the IBF flag set
commit 28fe5c825f8e15744d04c7c1b8df197950923ecd upstream. The EC driver works abnormally with IBF flag always set. IBF means "The host has written a byte of data to the command or data port, but the embedded controller has not yet read it". If IBF is set in the EC status and not cleared, this will cause all subsequent EC requests to fail with a timeout error. Change the EC driver so that it doesn't refuse to restart a transaction if IBF is set in the status. Also increase the number of transaction restarts to 5, as it turns out that 2 is not sufficient in some cases. This bug happens on several different machines (Asus V1S, Dell Latitude E6530, Samsung R719, Acer Aspire 5930G, Sony Vaio SR19VN and others). [rjw: Changelog] References: https://bugzilla.kernel.org/show_bug.cgi?id=14733 References: https://bugzilla.kernel.org/show_bug.cgi?id=15560 References: https://bugzilla.kernel.org/show_bug.cgi?id=15946 References: https://bugzilla.kernel.org/show_bug.cgi?id=42945 References: https://bugzilla.kernel.org/show_bug.cgi?id=48221 Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 1 insertions, 3 deletions
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index d45b2871d33..edc00818c80 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -223,7 +223,7 @@ static int ec_check_sci_sync(struct acpi_ec *ec, u8 state)
static int ec_poll(struct acpi_ec *ec)
unsigned long flags;
- int repeat = 2; /* number of command restarts */
+ int repeat = 5; /* number of command restarts */
while (repeat--) {
unsigned long delay = jiffies +
@@ -241,8 +241,6 @@ static int ec_poll(struct acpi_ec *ec)
advance_transaction(ec, acpi_ec_read_status(ec));
} while (time_before(jiffies, delay));
- if (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF)
- break;
pr_debug(PREFIX "controller reset, restart transaction\n");
spin_lock_irqsave(&ec->lock, flags);