- 18 8月, 2013 1 次提交
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由 Rafael J. Wysocki 提交于
After commit bbd34fcd (ACPI / hotplug / PCI: Register all devices under the given bridge) register_slot() is called for all PCI devices under a given bridge that have corresponding objects in the ACPI namespace, but it calls acpiphp_register_hotplug_slot() only for devices satisfying specific criteria. Still, cleanup_bridge() calls acpiphp_unregister_hotplug_slot() for all objects created by register_slot(), although it should only call it for the ones that acpiphp_register_hotplug_slot() has been called for (successfully). This causes a NULL pointer to be dereferenced by the acpiphp_unregister_hotplug_slot() executed by cleanup_bridge() if the object it is called for has not been passed to acpiphp_register_hotplug_slot(). To fix this problem, check if the 'slot' field of the object passed to acpiphp_unregister_hotplug_slot() in cleanup_bridge() is not NULL, which only is the case if acpiphp_register_hotplug_slot() has been executed for that object. In addition to that, make register_slot() reset the 'slot' field to NULL if acpiphp_register_hotplug_slot() has failed for the given object to prevent stale pointers from being used by acpiphp_unregister_hotplug_slot(). Reported-and-tested-by: NYinghai Lu <yinghai@kernel.org> Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
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- 01 8月, 2013 1 次提交
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由 Lan Tianyu 提交于
acpi_pci_set_power_state() uses dev_info() to print diagnostic messages regarding ACPI power state changes of devices, but that results in too much not really interesting output into the kernel log in some cases. For this reason, change it to use dev_dbg() instead and prevent kernel log from being spammed. [rjw: Changelog] References: https://bugzilla.kernel.org/show_bug.cgi?id=60636Suggested-by: NAlan Stern <stern@rowland.harvard.edu> Signed-off-by: NLan Tianyu <tianyu.lan@intel.com> Acked-by: NBjorn Helgaas <bhelgaas@google.com> Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
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- 23 7月, 2013 30 次提交
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由 Mika Westerberg 提交于
Now that acpiphp_check_bridge() always enumerates devices behind the bridge, there is no need to do that for each sub-bridge anymore like it is done in the current ACPI-based PCI hotplug (ACPIPHP) code. Given this we don't need check_sub_bridges() anymore, so drop that function completely. This also simplifies the ACPIPHP code a bit. Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
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由 Rafael J. Wysocki 提交于
Do not acquire bridge_mutex around the addition of a slot to its bridge's list of slots and arount the addition of a function to its slot's list of functions, because that doesn't help anything right now (those lists are walked without any locking anyway). However, acquire bridge_mutex around the list walk in acpiphp_remove_slots() and use list_for_each_entry() there, because we terminate the walk as soon as we find the first matching entry. This prevents that list walk from colliding with bridge addition and removal. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Rafael J. Wysocki 提交于
Notice that functions enable_device() and disable_device() cannot fail and their return values are ignored in the majority of places, so redefine them as void and use the opportunity to change their names to enable_slot() and disable_slot(), respectively, which much better reflects what they do. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Mika Westerberg 提交于
There is no need for a temporary variable and all the tricks with ternary operators in acpiphp_get_(latch)|(adapter)_status(). Change those functions to be a bit more straightforward. [rjw: Changelog] Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
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由 Mika Westerberg 提交于
Drop some unused symbols from acpiphp.h and redefine SLOT_ENABLED (which is the only slot flag now) as 1. [rjw: Redefinition of SLOT_ENABLED, changelog] Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
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由 Rafael J. Wysocki 提交于
The current implementation of acpiphp_check_bridge() is pretty dumb: - It enables a slot if it's not enabled and the slot status is ACPI_STA_ALL. - It disables a slot if it's enabled and the slot status is not ACPI_STA_ALL. This behavior is not sufficient to handle the Thunderbolt daisy chaining case properly, however, because in that case the bus behind the already enabled slot needs to be rescanned for new devices. For this reason, modify acpiphp_check_bridge() so that slots are disabled and stopped if they are not in the ACPI_STA_ALL state. For slots in the ACPI_STA_ALL state, devices behind them that don't respond are trimmed using a new function, trim_stale_devices(), introduced specifically for this purpose. That function walks the given bus and checks each device on it. If the device doesn't respond, it is assumed to be gone and is removed. Once all of the stale devices directy behind the slot have been removed, acpiphp_check_bridge() will start looking for new devices that might have appeared on the given bus. It will do that even if the slot is already enabled (SLOT_ENABLED is set for it). In addition to that, make the bus check notification ignore SLOT_ENABLED and go for enable_device() directly if bridge is NULL, so that devices behind the slot are re-enumerated in that case too. This change is based on earlier patches from Kirill A Shutemov and Mika Westerberg. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Kirill A. Shutemov 提交于
Currently, enable_device() checks the return value of pci_scan_slot() and returns immediately if that's 0 (meaning that no new functions have been found in the slot). However, if one of the functions in the slot is a bridge, some new devices may appear below it even if the bridge itself is present continuously, so it generally is necessary to do the rescan anyway just in case. [In particular, that's necessary with the Thunderbolt daisy chaining in which case new devices may be connected to the existing ones down the chain.] The correctness of this change relies on the ability of pcibios_resource_survey_bus() to detect if it has already been called for the given bus and to skip it if so. Failure to do that will lead to resource allocation conflicts. [rjw: Changelog] Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
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由 Kirill A. Shutemov 提交于
With Thunderbolt you can daisy chain devices: connect new devices to an already plugged one. In that case the "hotplug slot" is already enabled, but we still want to look for new PCI devices behind it. Reuse enable_device() to scan for new PCI devices on enabled slots and push the SLOT_ENABLED check up into acpiphp_enable_slot(). [rjw: Rebased, modified the changelog] Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
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由 Rafael J. Wysocki 提交于
The ACPI-based PCI hotplug (acpiphp) core code need not and really should not execute _PS0 and _PS3 directly for devices it handles. First of all, it is not necessary to put devices into D3 after acpi_bus_trim() has walked through them, because acpi_device_unregister() invoked by it puts each device into D3cold before returning. Thus after disable_device() the slot should be powered down already. Second, calling _PS0 directly on ACPI device objects may not be appropriate, because it may require power resources to be set up in a specific way in advance and that must be taken care of by the ACPI core. Thus modify acpiphp_bus_add() to power up the device using the appropriate interface after it has run acpi_bus_scan() on its handle. After that, the functions executing _PS0 and _PS3, power_on_slot() and power_off_slot(), are not necessary any more, so drop them and update the code calling them accordingly. Also drop the function flags related to device power states, since they aren't useful any more too. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Rafael J. Wysocki 提交于
Modify handle_hotplug_event() to avoid queing up the execution of handle_hotplug_event_work_fn() as a work item on kacpi_hotplug_wq for non-hotplug events, such as ACPI_NOTIFY_DEVICE_WAKE. Move the code printing diagnostic messages for those events into handle_hotplug_event(). In addition to that, remove the bogus comment about how the core should distinguish between hotplug and non-hotplug events and queue them up on different workqueues. The core clearly cannot know in advance what events will be interesting to the given caller of acpi_install_notify_handler(). Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Mika Westerberg 提交于
Both acpiphp_disable_slot() and acpiphp_eject_slot() are always called together so instead of calling each separately we can consolidate them into one function acpiphp_disable_and_eject_slot() that does both (but it will return success on _EJ0 failures that were ignored in the majority of call sites anyway). [rjw: Rebased plus minor tweaks] Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
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由 Rafael J. Wysocki 提交于
Two checks in check_hotplug_bridge() are redundant (they have been done by the caller already), so drop them. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Rafael J. Wysocki 提交于
The acpiphp_bus_trim() and acpiphp_bus_add() functions need not return error codes that are never checked, so redefine them and simplify them a bit. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Rafael J. Wysocki 提交于
To avoid chasing more pointers than necessary in some situations, move the bridge pointer from struct acpiphp_slot to struct acpiphp_func (and call it 'parent') and add a bus pointer to struct acpiphp_slot. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Rafael J. Wysocki 提交于
The handle field in struct acpiphp_bridge is only used by acpiphp_enumerate_slots(), but in that function the local handle variable can be used instead, so make that happen and drop handle from struct acpiphp_bridge. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Rafael J. Wysocki 提交于
The ACPI handle stored in struct acpiphp_func is also stored in the struct acpiphp_context object containing it and it is trivial to get from a struct acpiphp_func pointer to the handle field of the outer struct acpiphp_context. Hence, the handle field of struct acpiphp_func is redundant, so drop it and provide a helper function, func_to_handle(), allowing it users to get the ACPI handle for the given struct acpiphp_func pointer. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Rafael J. Wysocki 提交于
Since there has to be a struct acpiphp_func object for every struct acpiphp_context created by register_slot(), the struct acpiphp_func one can be embedded into the struct acpiphp_context one, which allows some code simplifications to be made. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Rafael J. Wysocki 提交于
The only bridge flag used by the ACPI-based PCI hotplug (ACPIPHP) code is BRIDGE_HAS_EJ0, but it is only used by the event handling function hotplug_event() and if that flag is set, the corresponding function flag FUNC_HAS_EJ0 is set as well, so that bridge flag is redundant. For this reason, drop BRIDGE_HAS_EJ0 and all code referring to it and since it is the only bridge flag defined, drop the flags field from struct acpiphp_bridge entirely. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Rafael J. Wysocki 提交于
If the slot unique number is passed as an additional argument to acpiphp_register_hotplug_slot(), the 'sun' field in struct acpiphp_slot is only used by ibm_[s|g]et_attention_status(), but then it's more efficient to store it in struct slot. Thus move the 'sun' field from struct acpiphp_slot to struct slot changing its data type to unsigned int in the process, and redefine acpiphp_register_hotplug_slot() to take the slot number as separate argument. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Rafael J. Wysocki 提交于
Rework register_slot() to create a struct acpiphp_func object for every function it is called for and to create acpiphp slots for all of them. Although acpiphp_register_hotplug_slot() is only called for the slots whose functions are identified as "ejectable", so that user space can manipulate them, the ACPIPHP notify handler, handle_hotplug_event(), is now installed for all of the registered functions (that aren't dock stations) and hotplug events may be handled for all of them. As a result, essentially, all PCI bridges represented by objects in the ACPI namespace are now going to be "hotplug" bridges and that may affect resources allocation in general, although it shouldn't lead to problems. This allows the code to be simplified substantially and addresses the problem where bus check or device check notifications for some PCI bridges or devices are not handled, because those devices are not recognized as "ejectable" or there appear to be no "ejectable" devices under those bridges. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Rafael J. Wysocki 提交于
To make the code in register_slot() a bit easier to follow, change the way the slot allocation part is organized. Drop one local variable that's not used any more after that modification. This code change should not lead to any changes in behavior. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Rafael J. Wysocki 提交于
Since the func pointer in struct acpiphp_context can always be used instead of the func pointer in struct acpiphp_bridge, drop the latter. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Rafael J. Wysocki 提交于
There are separate handling event functions for hotplug bridges and for hotplug functions, but they may be combined into one common hotplug event handling function which simplifies the code slightly. That also allows a theoretical bug to be dealt with which in principle may occur if a hotplug bridge is on a dock station, because in that case the bridge-specific notification should be used instead of the function-specific one, but the dock station always uses the latter. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Rafael J. Wysocki 提交于
Modify handle_hotplug_event() to pass the entire context object (instead of its fields individually) to work functions started by it. This change makes the subsequent consolidation of the event handling work functions a bit more straightforward. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Rafael J. Wysocki 提交于
Using the hotplug context objects introduced previously rework the ACPI-based PCI hotplug (ACPIPHP) core code to get to acpiphp_bridge objects associated with hotplug bridges from those context objects rather than from the global list of hotplug bridges. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Rafael J. Wysocki 提交于
Using the hotplug context objects introduced previously rework the ACPI-based PCI hotplug (ACPIPHP) core code so that all notifications for ACPI device objects corresponding to the hotplug PCI devices are handled by one function, handle_hotplug_event(), which recognizes whether it has to handle a bridge or a function. In addition to code size reduction it allows some ugly pieces of code where notify handlers have to be uninstalled and installed again to go away. Moreover, it fixes a theoretically possible race between handle_hotplug_event() and free_bridge() tearing down data structures for the same handle. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Rafael J. Wysocki 提交于
When either a new hotplug bridge or a new hotplug function is added by the ACPI-based PCI hotplug (ACPIPHP) code, attach a context object to its ACPI handle to store hotplug-related information in it. To start with, put the handle's bridge and function pointers into that object. Count references to the context objects and drop them when they are not needed any more. First of all, this makes it possible to find out if the given bridge has been registered as a function already in a much more straightforward way and acpiphp_bridge_handle_to_function() can be dropped (Yay!). This also will allow some more simplifications to be made going forward. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Rafael J. Wysocki 提交于
When a new ACPIPHP function is added by register_slot() and the notify handler cannot be installed for it, register_slot() returns an error status without cleaning up, which causes the entire namespace walk in acpiphp_enumerate_slots() to be aborted, although it still may be possible to successfully install the function notify handler for other device objects under the given brigde. To address this issue make register_slot() return success after a new function has been added, even if the addition of the notify handler for it has failed. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Rafael J. Wysocki 提交于
The acpiphp_enumerate_slots() function is now split into two parts, acpiphp_enumerate_slots() proper and init_bridge_misc() which is only called by the former. If these functions are combined, it is possible to make the code easier to follow and to clean up the error handling (to prevent memory leaks on error from happening in particular), so do that. Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
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由 Rafael J. Wysocki 提交于
Since acpi_pci_slot_enumerate() and acpiphp_enumerate_slots() can get the ACPI device handle they need from bus->bridge, it is not necessary to pass that handle to them as an argument. Drop the second argument of acpi_pci_slot_enumerate() and acpiphp_enumerate_slots(), rework them to obtain the ACPI handle from bus->bridge and make acpi_pci_add_bus() and acpi_pci_remove_bus() entirely symmetrical. Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: NYinghai Lu <yinghai@kernel.org>
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- 19 7月, 2013 4 次提交
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由 Ingo Tuchscherer 提交于
The zcrypt device driver has been split into base/bus module, api-module, card modules and message type modules. The base module has been renamed from z90crypt to ap. A module alias (with the well-known z90crypt identifier) will be introduced that enable users to use their existing way to load the zcrypt device driver. Signed-off-by: NIngo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com> Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
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由 Jason Wang 提交于
We try to linearize part of the skb when the number of iov is greater than MAX_SKB_FRAGS. This is not enough since each single vector may occupy more than one pages, so zerocopy_sg_fromiovec() may still fail and may break the guest network. Solve this problem by calculate the pages needed for iov before trying to do zerocopy and switch to use copy instead of zerocopy if it needs more than MAX_SKB_FRAGS. This is done through introducing a new helper to count the pages for iov, and call uarg->callback() manually when switching from zerocopy to copy to notify vhost. We can do further optimization on top. This bug were introduced from b92946e2 (macvtap: zerocopy: validate vectors before building skb). Cc: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: NJason Wang <jasowang@redhat.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Jason Wang 提交于
We try to linearize part of the skb when the number of iov is greater than MAX_SKB_FRAGS. This is not enough since each single vector may occupy more than one pages, so zerocopy_sg_fromiovec() may still fail and may break the guest network. Solve this problem by calculate the pages needed for iov before trying to do zerocopy and switch to use copy instead of zerocopy if it needs more than MAX_SKB_FRAGS. This is done through introducing a new helper to count the pages for iov, and call uarg->callback() manually when switching from zerocopy to copy to notify vhost. We can do further optimization on top. The bug were introduced from commit 0690899b (tun: experimental zero copy tx support) Cc: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: NJason Wang <jasowang@redhat.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Lan Tianyu 提交于
The BIOS of FUjitsu E753 reports an incorrect initial backlight value for WIN8 compatible OS, causing backlight to be dark during startup. This change causes the incorrect initial value from BIOS to be ignored. References: https://bugzilla.kernel.org/show_bug.cgi?id=60161Reported-and-tested-by: NJan Hinnerk Stosch <janhinnerk.stosch@gmail.com> Signed-off-by: NLan Tianyu <tianyu.lan@intel.com> Cc: 3.7+ <stable@vger.kernel.org> Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
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- 18 7月, 2013 4 次提交
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由 NeilBrown 提交于
Recent change to use bio_copy_data() in raid1 when repairing an array is faulty. The underlying may have changed the bio in various ways using bio_advance and these need to be undone not just for the 'sbio' which is being copied to, but also the 'pbio' (primary) which is being copied from. So perform the reset on all bios that were read from and do it early. This also ensure that the sbio->bi_io_vec[j].bv_len passed to memcmp is correct. This fixes a crash during a 'check' of a RAID1 array. The crash was introduced in 3.10 so this is suitable for 3.10-stable. Cc: stable@vger.kernel.org (3.10) Reported-by: NJoe Lawrence <joe.lawrence@stratus.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
commit 7ceb17e8 md: Allow devices to be re-added to a read-only array. allowed a bit more than just that. It also allows devices to be added to a read-write array and to end up skipping recovery. This patch removes the offending piece of code pending a rewrite for a subsequent release. More specifically: If the array has a bitmap, then the device will still need a bitmap based resync ('saved_raid_disk' is set under different conditions is a bitmap is present). If the array doesn't have a bitmap, then this is correct as long as nothing has been written to the array since the metadata was checked by ->validate_super. However there is no locking to ensure that there was no write. Bug was introduced in 3.10 and causes data corruption so patch is suitable for 3.10-stable. Cc: stable@vger.kernel.org (3.10) Reported-by: NJoe Lawrence <joe.lawrence@stratus.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
1/ When an different between blocks is found, data is copied from one bio to the other. However bv_len is used as the length to copy and this could be zero. So use r10_bio->sectors to calculate length instead. Using bv_len was probably always a bit dubious, but the introduction of bio_advance made it much more likely to be a problem. 2/ When preparing some blocks for sync, we don't set BIO_UPTODATE except on bios that we schedule for a read. This ensures that missing/failed devices don't confuse the loop at the top of sync_request write. Commit 8be185f2 "raid10: Use bio_reset()" removed a loop which set BIO_UPTDATE on all appropriate bios. So we need to re-add that flag. These bugs were introduced in 3.10, so this patch is suitable for 3.10-stable, and can remove a potential for data corruption. Cc: stable@vger.kernel.org (3.10) Reported-by: NBrassow Jonathan <jbrassow@redhat.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 Aaron Lu 提交于
Starting from win8, MS backlight control driver will set bit 2 of the parameter of control method _DOS, to inform firmware it should not perform any automatic brightness changes. This mostly affects hotkey notification deliver - if we do not set this bit, on hotkey press, firmware may choose to adjust brightness level instead of sending out notification and doing nothing. So this patch sets bit 2 when calling _DOS so that GUIs can show the notification window on hotkey press. This behavior change is only necessary for win8 systems. The MS document on win8 backlight control is here: http://msdn.microsoft.com/en-US/library/windows/hardware/jj159305 References: https://bugzilla.kernel.org/show_bug.cgi?id=52951 References: https://bugzilla.kernel.org/show_bug.cgi?id=56711Reported-by: NMicael Dias <kam1kaz3@gmail.com> Reported-by: NDan Garton <dan.garton@gmail.com> Reported-by: NBob Ziuchkovski <bob.ziuchkovski@gmail.com> Signed-off-by: NAaron Lu <aaron.lu@intel.com> Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
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