> that's really nasty EC firmware!
Yes!
And this bug has been unsolved for about two years.
> 20 is enough?
> the query index is length of a byte.
>
According to our humble tests, 8 is the maximum number of
accumulated events. For instance, if the one plugs or unplugs the PSU
16 times, (or battery % changes 16 times) during S3 sleep, then the
EC returns no more than 8 events when polled by this patch or by
my userspace util.
And having reached 8 events, it won't produce its GPE until queried.
> the query index is length of a byte.
There is no query index, unless you refer to something else (I'm sorry if its
something that escapes me).
For us, a query is just: send 0x84 through EC CMD port, and read status
from CMD port and event type from EC DATA port. This is done with
the usual ec.c functions that would handle a query after a GPE interrupt,
but using them instead to poll (not GPE initiated) at awake. The EC would
then return status without 0x20 mask and 'event type'==0 when no more left.
--
Juan Manuel Cabo <juanmanuel.cabo@xxxxxxxxx>
>>
>> enum {
>> EC_FLAGS_QUERY_PENDING, /* Query is pending */
>> @@ -116,6 +118,7 @@ EXPORT_SYMBOL(first_ec);
>> static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */
>> static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */
>> static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */
>> +static int EC_FLAGS_CLEAR_ON_RESUME; /* EC should be polled on boot/resume */
>>
>
> seems name is implicit, what about EC_FLAGS_QEVENT_CLR_ON_RESUME?
> seems too long :-)
>
>>
>> /* --------------------------------------------------------------------------
>> Transaction Management
>> @@ -440,6 +443,26 @@ acpi_handle ec_get_handle(void)
>>
>> EXPORT_SYMBOL(ec_get_handle);
>>
>> +static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 *data);
>> +
>> +/* run with locked ec mutex */
>> +static void acpi_ec_clear(struct acpi_ec *ec)
>> +{
>> + int i, status;
>> + u8 value = 0;
>> +
>> + for (i = 0; i< ACPI_EC_CLEAR_MAX; i++) {
>> + status = acpi_ec_query_unlocked(ec,&value);
>> + if (status || !value)
>> + break;
>> + }
>> +
>> + if (i == ACPI_EC_CLEAR_MAX)
>> + pr_warn("Warning: Maximum of %d stale EC events cleared\n", i);
>> + else
>> + pr_info("%d stale EC events cleared\n", i);
>> +}
>> +
>> void acpi_ec_block_transactions(void)
>> {
>> struct acpi_ec *ec = first_ec;
>> @@ -463,6 +486,10 @@ void acpi_ec_unblock_transactions(void)
>> mutex_lock(&ec->mutex);
>> /* Allow transactions to be carried out again */
>> clear_bit(EC_FLAGS_BLOCKED,&ec->flags);
>> +
>> + if (EC_FLAGS_CLEAR_ON_RESUME)
>> + acpi_ec_clear(ec);
>> +
>> mutex_unlock(&ec->mutex);
>> }
>>
>> @@ -821,6 +848,13 @@ static int acpi_ec_add(struct acpi_device *device)
>>
>> /* EC is fully operational, allow queries */
>> clear_bit(EC_FLAGS_QUERY_PENDING,&ec->flags);
>> +
>> + /* Some hardware may need the EC to be cleared before use */
>>
>
> description is implicit, should specify what we clear is Q event, not EC.
>
> Thanks!
> Li Guang
>
>> + if (EC_FLAGS_CLEAR_ON_RESUME) {
>> + mutex_lock(&ec->mutex);
>> + acpi_ec_clear(ec);
>> + mutex_unlock(&ec->mutex);
>> + }
>> return ret;
>> }
>>
>> @@ -922,6 +956,30 @@ static int ec_enlarge_storm_threshold(const struct dmi_system_id *id)
>> return 0;
>> }
>>
>> +/*
>> + * On some hardware it is necessary to clear events accumulated by the EC during
>> + * sleep. These ECs stop reporting GPEs until they are manually polled, if too
>> + * many events are accumulated. (e.g. Samsung Series 5/9 notebooks)
>> + *
>> + * https://bugzilla.kernel.org/show_bug.cgi?id=44161
>> + *
>> + * Ideally, the EC should also be instructed not to accumulate events during
>> + * sleep (which Windows seems to do somehow), but the interface to control this
>> + * behaviour is not known at this time.
>> + *
>> + * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx,
>> + * however it is very likely that other Samsung models are affected.
>> + *
>> + * On systems which don't accumulate EC events during sleep, this extra check
>> + * should be harmless.
>> + */
>> +static int ec_clear_on_resume(const struct dmi_system_id *id)
>> +{
>> + pr_debug("Detected system needing EC poll on resume.\n");
>> + EC_FLAGS_CLEAR_ON_RESUME = 1;
>> + return 0;
>> +}
>> +
>> static struct dmi_system_id ec_dmi_table[] __initdata = {
>> {
>> ec_skip_dsdt_scan, "Compal JFL92", {
>> @@ -965,6 +1023,9 @@ static struct dmi_system_id ec_dmi_table[] __initdata = {
>> ec_validate_ecdt, "ASUS hardware", {
>> DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."),
>> DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL},
>> + {
>> + ec_clear_on_resume, "Samsung hardware", {
>> + DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL},
>> {},
>> };
>>
>>
>
>
--
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
