On 11/26/2015 06:45 PM, Andy Shevchenko wrote:
On Thu, 2015-11-26 at 18:30 +0200, Jarkko Nikula wrote:
On 11/26/2015 05:19 PM, Andy Shevchenko wrote:
This is an amendment to previously pushed commit 01ac170ba29a (ACPI
/ LPSS:
allow to use specific PM domain during ->probe()). We can't assign
anything to
the platform device on ADD_DEVICE stage since it might be changed
during
unbound / bind cycle.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/acpi/acpi_lpss.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
index f9e0d09..e840229 100644
--- a/drivers/acpi/acpi_lpss.c
+++ b/drivers/acpi/acpi_lpss.c
@@ -705,8 +705,14 @@ static int acpi_lpss_platform_notify(struct
notifier_block *nb,
}
switch (action) {
- case BUS_NOTIFY_ADD_DEVICE:
+ case BUS_NOTIFY_BIND_DRIVER:
pdev->dev.pm_domain = &acpi_lpss_pm_domain;
+ break;
+ case BUS_NOTIFY_BIND_DRIVER_ERROR:
+ case BUS_NOTIFY_UNBOUND_DRIVER:
+ pdev->dev.pm_domain = NULL;
+ break;
+ case BUS_NOTIFY_ADD_DEVICE:
This won't fix like revert of original commit does. Primary problem
here
is that there is no explicit power on at all during LPSS device probe
because dev->pm_domain is set before probing.
And we can't do this as in very original code of acpi_lpss.c since DMA
has to be sure it's powered on while probing. We could guarantee this
only in case when PM domain is assigned already and we do our quirk for
it.
I'm not sure do I follow here. Is the power on chain different for LPSS
DMA because setting the domain at BIND stage prevents the call to
acpi_dev_pm_full_power() before driver probe? See below.
driver_probe_device
really_probe
driver_sysfs_add -> BUS_NOTIFY_BIND_DRIVER
-> platform_drv_prove
dev_pm_domain_attach
acpi_dev_pm_attach
if (dev->pm_domain) return -EEXIST;
...
if (power_on) { acpi_dev_pm_full_power(adev);... }
-> probe
driver_bound -> BUS_NOTIFY_BOUND_DRIVER
From my point of view we have to fix hang first since it's most painful
case for users and their experience. Though I'm open to any better
solution if you have any in mind.
Sure.
--
Jarkko
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