Re: [Update][PATCH 4/5][RFT] ACPI / hotplug / PCI: Simplifyacpi_install_hotplug_notify_handler()

From: Mika Westerberg
Date: Fri Jan 31 2014 - 10:55:12 EST


On Fri, Jan 31, 2014 at 05:40:11PM +0200, Mika Westerberg wrote:
> On Fri, Jan 31, 2014 at 04:42:21PM +0100, Rafael J. Wysocki wrote:
> > On Friday, January 31, 2014 05:28:36 PM Mika Westerberg wrote:
> > > On Wed, Jan 29, 2014 at 01:00:57AM +0100, Rafael J. Wysocki wrote:
> > > > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> > > >
> > > > Use the observation that the ACPI scan handler of the device object
> > > > in acpi_hotplug_notify_cb() can be obtained from that device object's
> > > > handler pointer and do not pass it as data to
> > > > acpi_install_hotplug_notify_handler() in acpi_scan_init_hotplug().
> > > >
> > > > That allows the second argument of acpi_install_hotplug_notify_handler()
> > > > to be dropped, so do it and update its callers accordingly.
> > > >
> > > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> > > > ---
> > > > drivers/acpi/scan.c | 31 ++++++++++++++++++-------------
> > > > drivers/pci/hotplug/acpiphp_glue.c | 2 +-
> > > > include/acpi/acpi_bus.h | 2 +-
> > > > 3 files changed, 20 insertions(+), 15 deletions(-)
> > > >
> > > > Index: linux-pm/drivers/acpi/scan.c
> > > > ===================================================================
> > > > --- linux-pm.orig/drivers/acpi/scan.c
> > > > +++ linux-pm/drivers/acpi/scan.c
> > > > @@ -487,7 +487,6 @@ static void acpi_device_hotplug(void *da
> > > >
> > > > static void acpi_hotplug_notify_cb(acpi_handle handle, u32 type, void *data)
> > > > {
> > > > - struct acpi_scan_handler *handler = data;
> > > > u32 ost_code = ACPI_OST_SC_SUCCESS;
> > > > struct acpi_device *adev;
> > > > acpi_status status;
> > > > @@ -503,13 +502,6 @@ static void acpi_hotplug_notify_cb(acpi_
> > > >
> > > > case ACPI_NOTIFY_EJECT_REQUEST:
> > > > acpi_handle_debug(handle, "ACPI_NOTIFY_EJECT_REQUEST event\n");
> > > > - if (handler && !handler->hotplug.enabled) {
> > > > - acpi_handle_err(handle, "Eject disabled\n");
> > > > - ost_code = ACPI_OST_SC_EJECT_NOT_SUPPORTED;
> > > > - goto out;
> > > > - }
> > > > - acpi_evaluate_hotplug_ost(handle, ACPI_NOTIFY_EJECT_REQUEST,
> > > > - ACPI_OST_SC_EJECT_IN_PROGRESS, NULL);
> > > > break;
> > > >
> > > > case ACPI_NOTIFY_DEVICE_WAKE:
> > > > @@ -535,11 +527,24 @@ static void acpi_hotplug_notify_cb(acpi_
> > > > goto out;
> > > > }
> > > >
> > > > + mutex_lock(&acpi_scan_lock);
> > >
> > > This is weird. I'm testing against your test-next branch which has this
> > > patch included. If I remove locking here, TBT hotplug works fine. Otherwise
> > > I can see the first hotplug/unplug works but after that I cannot get any
> > > events anymore.
> >
> > Weird indeed. I don't seem to be able to reproduce that on my Aspire S5.
> >
> > What system are you testing on?
>
> This is Intel NUC. Let me see if I can reproduce this on S5 with longer
> chain of devices.

OK, so on S5 this works even with longer chain. However, exactly the same
kernel image on NUC fails after first hotplug/unplug cycle.
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