kernel.git/drivers/pci/hotplug/shpchp.h, branch linux-3.2.y

PCI: shpchp: Use per-slot workqueues to avoid deadlock

2013-02-06T04:33:33Z

commit f652e7d2916fe2fcf9e7d709aa5b7476b431e2dd upstream. When we have an SHPC-capable bridge with a second SHPC-capable bridge below it, pushing the upstream bridge's attention button causes a deadlock. The deadlock happens because we use the shpchp_wq workqueue to run shpchp_pushbutton_thread(), which uses shpchp_disable_slot() to remove devices below the upstream bridge. When we remove the downstream bridge, we call shpc_remove(), the shpchp driver's .remove() method. That calls flush_workqueue(shpchp_wq), which deadlocks because the shpchp_pushbutton_thread() work item is still running. This patch avoids the deadlock by creating a workqueue for every slot and removing the single shared workqueue. Here's the call path that leads to the deadlock: shpchp_queue_pushbutton_work queue_work(shpchp_wq) # shpchp_pushbutton_thread ... shpchp_pushbutton_thread shpchp_disable_slot remove_board shpchp_unconfigure_device pci_stop_and_remove_bus_device ... shpc_remove # shpchp driver .remove method hpc_release_ctlr cleanup_slots flush_workqueue(shpchp_wq) This change is based on code inspection, since we don't have hardware with this topology. Based-on-patch-by: Yijing Wang Signed-off-by: Bjorn Helgaas [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings

PCI: shpchp: Handle push button event asynchronously

2013-02-06T04:33:33Z

commit d347e75847c1fb299c97736638f45e6ea39702d4 upstream. Use non-ordered workqueue for attention button events. Attention button events on each slot can be handled asynchronously. So we should use non-ordered workqueue. This patch also removes ordered workqueue in shpchp as a result. 486b10b9f4 ("PCI: pciehp: Handle push button event asynchronously") made the same change to pciehp. I split this out from a patch by Yijing Wang so we fix one thing at a time and to make the shpchp history correspond more closely with the pciehp history. Signed-off-by: Bjorn Helgaas CC: Kenji Kaneshige Signed-off-by: Ben Hutchings

shpchp: update workqueue usage

2010-10-18T06:33:02Z

* Rename shpchp_wq to shpchp_ordered_wq and add non-ordered shpchp_wq which is used instead of the system workqueue. This is to remove the use of flush_scheduled_work() which is deprecated and scheduled for removal. * With cmwq in place, there's no point in creating workqueues lazily. Create both shpchp_wq and shpchp_ordered_wq upfront. * Include workqueue.h from shpchp.h. Signed-off-by: Tejun Heo Acked-by: Jesse Barnes

PCI: Make current and maximum bus speeds part of the PCI core

2010-02-23T00:15:17Z

Move the max_bus_speed and cur_bus_speed into the pci_bus. Expose the values through the PCI slot driver instead of the hotplug slot driver. Update all the hotplug drivers to use the pci_bus instead of their own data structures. Signed-off-by: Matthew Wilcox Signed-off-by: Jesse Barnes

PCI: change PCI nomenclature in drivers/pci/ (comment changes)

2009-12-16T21:37:53Z

Changing occurrences of variants of PCI-X and PCIe to the PCI-SIG terms listed in the "Trademark and Logo Usage Guidelines". http://www.pcisig.com/developers/procedures/logos/Trademark_and_Logo_Usage_Guidelines_updated_112206.pdf Patch is limited to drivers/pci/ and changes concern comments only. Signed-off-by: Stefan Assmann Signed-off-by: Jesse Barnes

PCI hotplug: shpchp: use generic pci_configure_slot()

2009-09-15T00:39:11Z

Use the generic pci_configure_slot() rather than the SHPC-specific program_fw_provided_values(). Unlike the previous SHPC-specific code, pci_configure_slot() programs PCIe settings when an _HPX method provides them, so if it's possible to have an SHPC-managed PCIe device, it can now be configured. Signed-off-by: Bjorn Helgaas Reviewed-by: Kenji Kaneshige Acked-by: Kenji Kaneshige Signed-off-by: Jesse Barnes

PCI hotplug: clean up acpi_get_hp_params_from_firmware() interface

2009-09-15T00:38:26Z

This patch makes acpi_get_hp_params_from_firmware() take a pci_dev rather than a pci_bus and makes it return a standard int errno rather than acpi_status. Signed-off-by: Bjorn Helgaas Reviewed-by: Kenji Kaneshige Acked-by: Kenji Kaneshige Signed-off-by: Jesse Barnes

PCI: add missing KERN_* constants to printks

2009-03-20T02:29:27Z

According to kerneljanitors todo list all printk calls (beginning a new line) should have an according KERN_* constant. Those are the missing pieces here for the pci subsystem. Signed-off-by: Frank Seidel Reviewed-by: Kenji Kaneshige Tested-by: Kenji Kaneshige Signed-off-by: Jesse Barnes

PCI hotplug: shpchp: message refinement

2008-10-23T23:14:00Z

This patch refines messages in shpchp module. The main changes are as follows: - remove the trailing "." - remove __func__ as much as possible - capitalize the first letter of messages - show PCI device address including its domain Signed-off-by: Taku Izumi Signed-off-by: Jesse Barnes

PCI hotplug: shpchp: replace printk with dev_printk

2008-10-23T23:11:50Z

This patch replaces printks within shpchp module with dev_printks. Signed-off-by: Taku Izumi Signed-off-by: Jesse Barnes