On Monday, May 06, 2013 11:23:40 AM Lan Tianyu wrote: > Some time, EC works abnormally with IBF flag always setting. > 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". > This will cause all EC requests to be failed with timeout error. > > After several trials, find restarting transaction with IBF flag > setting can make EC work again. This patch is to remove the > IBF flag check before restarting transaction and increase the > repeat number to 5. Some time, once restart is not enough. > > This bug happens on the different machines. (e.g Asus V1S, > Dell Latitude E6530, Samsung R719, Acer Aspire 5930G, > Sony Vaio SR19VN and so on). > > Related bugs: > https://bugzilla.kernel.org/show_bug.cgi?id=14733 > https://bugzilla.kernel.org/show_bug.cgi?id=15560 > https://bugzilla.kernel.org/show_bug.cgi?id=15946 > https://bugzilla.kernel.org/show_bug.cgi?id=42945 > https://bugzilla.kernel.org/show_bug.cgi?id=48221 > > Signed-off-by: Lan Tianyu <tianyu.lan@xxxxxxxxx> Queued up for a post-3.10-rc1 push as 3.10 (and -stable) material. Thanks, Rafael > --- > drivers/acpi/ec.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c > index d45b287..edc0081 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 + > msecs_to_jiffies(ec_delay); > @@ -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); > start_transaction(ec); > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
