Henrique de Moraes Holschuh wrote:
On Mon, 01 Sep 2008, Zhao Yakui wrote:
Will the above two patches hit the upstream kernel? If the above two patches hits the upstream kernel, it
seems that the boot option of "ec_intr=" comes back again and EC can't be switched from interrupt mode to polling
mode if EC GPE interrupt is missing. In such case maybe the battery/AC/thermal driver can't work well if the info of
battery/AC/thermal is related with EC. Maybe there exists the regression on some laptops.
Right now, the fact that it gives up on interrupt mode too easily IS causing
regressions on ThinkPads (like the T43 I own). Since polling mode does
work, it is just a performance regression, so you won't get many reports
about it since most people don't look for such stuff in their kernel logs.
Some ECs trigger the interrupt/poll-mode checks just on small windows
(typically during resume -- might even be a bug somewhere in ACPICA or
Linux, and not on the EC). We should not be giving up using interrupt mode
on these so easily. Maybe retry enabling interrupt mode after some seconds
a few times (like 3 or 5)? If it is a transient problem, that will avoid
the permanent performance regression of polled mode.
How about such patch?
Regards,
Alex.
ACPI: EC: retry gpe mode after 5 sec timeout
From: Alexey Starikovskiy <astarikovskiy@xxxxxxx>
Signed-off-by: Alexey Starikovskiy <astarikovskiy@xxxxxxx>
---
drivers/acpi/ec.c | 8 +++++++-
1 files changed, 7 insertions(+), 1 deletions(-)
diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index f338d2b..15663c2 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -74,6 +74,7 @@ enum ec_event {
#define ACPI_EC_DELAY 500 /* Wait 500ms max. during EC ops */
#define ACPI_EC_UDELAY_GLK 1000 /* Wait 1ms max. to get global lock */
#define ACPI_EC_UDELAY 100 /* Wait 100us before polling EC again */
+#define ACPI_EC_GPE_RETRY 5000 /* Wait 5s before trying to use GPE again */
enum {
EC_FLAGS_WAIT_GPE = 0, /* Don't check status until GPE arrives */
@@ -102,6 +103,7 @@ static struct acpi_ec {
unsigned long data_addr;
unsigned long global_lock;
unsigned long flags;
+ unsigned long gpe_retry;
struct mutex lock;
wait_queue_head_t wait;
struct list_head list;
@@ -205,6 +207,9 @@ static int acpi_ec_wait(struct acpi_ec *ec, enum ec_event event, int force_poll)
"switch off interrupt mode.\n");
set_bit(EC_FLAGS_NO_GPE, &ec->flags);
clear_bit(EC_FLAGS_GPE_MODE, &ec->flags);
+ /* check again in 5 seconds */
+ ec->gpe_retry = jiffies +
+ msecs_to_jiffies(ACPI_EC_GPE_RETRY);
return 0;
}
} else {
@@ -530,7 +535,8 @@ static u32 acpi_ec_gpe_handler(void *data)
acpi_ec_gpe_query, ec);
} else if (!test_bit(EC_FLAGS_GPE_MODE, &ec->flags) &&
!test_bit(EC_FLAGS_NO_GPE, &ec->flags) &&
- in_interrupt()) {
+ in_interrupt() &&
+ !time_before(jiffies, ec->gpe_retry)) {
/* this is non-query, must be confirmation */
if (printk_ratelimit())
pr_info(PREFIX "non-query interrupt received,"
