If a timeout is hit, it can result is incorrect data on the I2C bus
and/or memory corruptions in the guest since the device can still be
operating on the buffers it was given while the guest has freed them.

Here is, for example, the start of a slub_debug splat which was
triggered on the next transfer after one transfer was forced to timeout
by setting a breakpoint in the backend (rust-vmm/vhost-device):

 BUG kmalloc-1k (Not tainted): Poison overwritten
 First byte 0x1 instead of 0x6b
 Allocated in virtio_i2c_xfer+0x65/0x35c age=350 cpu=0 pid=29
 	__kmalloc+0xc2/0x1c9
 	virtio_i2c_xfer+0x65/0x35c
 	__i2c_transfer+0x429/0x57d
 	i2c_transfer+0x115/0x134
 	i2cdev_ioctl_rdwr+0x16a/0x1de
 	i2cdev_ioctl+0x247/0x2ed
 	vfs_ioctl+0x21/0x30
 	sys_ioctl+0xb18/0xb41
 Freed in virtio_i2c_xfer+0x32e/0x35c age=244 cpu=0 pid=29
 	kfree+0x1bd/0x1cc
 	virtio_i2c_xfer+0x32e/0x35c
 	__i2c_transfer+0x429/0x57d
 	i2c_transfer+0x115/0x134
 	i2cdev_ioctl_rdwr+0x16a/0x1de
 	i2cdev_ioctl+0x247/0x2ed
 	vfs_ioctl+0x21/0x30
 	sys_ioctl+0xb18/0xb41

There is no simple fix for this (the driver would have to always create
bounce buffers and hold on to them until the device eventually returns
the buffers), so just disable the timeout support for now.

Fixes: 3cfc88380413d20f ("i2c: virtio: add a virtio i2c frontend driver")
Acked-by: Jie Deng <jie.deng@intel.com>
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Currently interrupt storm will occur from i2c-i801 after first
transaction if SMB_ALERT signal is enabled and ever asserted. It is
enough if the signal is asserted once even before the driver is loaded
and does not recover because that interrupt is not acknowledged.

This fix aims to fix it by two ways:
- Add acknowledging for the SMB_ALERT interrupt status
- Disable the SMB_ALERT interrupt on platforms where possible since the
  driver currently does not make use for it

Acknowledging resets the SMB_ALERT interrupt status on all platforms and
also should help to avoid interrupt storm on older platforms where the
SMB_ALERT interrupt disabling is not available.

For simplicity this fix reuses the host notify feature for disabling and
restoring original register value.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=177311
Reported-by: ck+kernelbugzilla@bl4ckb0x.de
Reported-by: stephane.poignant@protonmail.com
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Tested-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

If driver interrupts are enabled, SMBHSTCNT_INTREN will be 1 after
the first transaction, and will stay to that value forever. This
means that interrupts will be generated for both host-initiated
transactions and also SMBus Alert events even after the driver is
unloaded. To be on the safe side, we should restore the initial state
of this bit at suspend and reboot time, as we do for several other
configuration bits already and for the same reason: the BIOS should
be handed the device in the same configuration state in which we
received it. Otherwise interrupts may be generated which nobody
will process.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Pull more ACPI updates from Rafael Wysocki:
 "These add support for a new ACPI device configuration object called
  _DSC, fix some issues including one recent regression, add two new
  items to quirk lists and clean up assorted pieces of code.

  Specifics:

   - Add support for new ACPI device configuration object called _DSC
     ("Deepest State for Configuration") to allow certain devices to be
     probed without changing their power states, document it and make
     two drivers use it (Sakari Ailus, Rajmohan Mani).

   - Fix device wakeup power reference counting broken recently by
     mistake (Rafael Wysocki).

   - Drop unused symbol and macros depending on it from acgcc.h (Rafael
     Wysocki).

   - Add HP ZHAN 66 Pro to the "no EC wakeup" quirk list (Binbin Zhou).

   - Add Xiaomi Mi Pad 2 to the backlight quirk list and drop an unused
     piece of data from all of the list entries (Hans de Goede).

   - Fix register read accesses handling in the Intel PMIC operation
     region driver (Hans de Goede).

   - Clean up static variables initialization in the EC driver
     (wangzhitong)"

* tag 'acpi-5.16-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Documentation: ACPI: Fix non-D0 probe _DSC object example
  ACPI: Drop ACPI_USE_BUILTIN_STDARG ifdef from acgcc.h
  ACPI: PM: Fix device wakeup power reference counting error
  ACPI: video: use platform backlight driver on Xiaomi Mi Pad 2
  ACPI: video: Drop dmi_system_id.ident settings from video_detect_dmi_table[]
  ACPI: PMIC: Fix intel_pmic_regs_handler() read accesses
  ACPI: EC: Remove initialization of static variables to false
  ACPI: EC: Use ec_no_wakeup on HP ZHAN 66 Pro
  at24: Support probing while in non-zero ACPI D state
  media: i2c: imx319: Support device probe in non-zero ACPI D state
  ACPI: Add a convenience function to tell a device is in D0 state
  Documentation: ACPI: Document _DSC object usage for enum power state
  i2c: Allow an ACPI driver to manage the device's power state during probe
  ACPI: scan: Obtain device's desired enumeration power state

Pull i2c updates from Wolfram Sang:

 - big refactoring of the PASEMI driver to support the Apple M1

 - huge improvements to the XIIC in terms of locking and SMP safety

 - refactoring and clean ups for the i801 driver

... and the usual bunch of small driver updates

* 'i2c/for-mergewindow' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (43 commits)
  i2c: amd-mp2-plat: ACPI: Use ACPI_COMPANION() directly
  i2c: i801: Add support for Intel Ice Lake PCH-N
  i2c: virtio: update the maintainer to Conghui
  i2c: xlr: Fix a resource leak in the error handling path of 'xlr_i2c_probe()'
  i2c: qup: move to use request_irq by IRQF_NO_AUTOEN flag
  i2c: qup: fix a trivial typo
  i2c: tegra: Ensure that device is suspended before driver is removed
  i2c: i801: Fix incorrect and needless software PEC disabling
  i2c: mediatek: Dump i2c/dma register when a timeout occurs
  i2c: mediatek: Reset the handshake signal between i2c and dma
  i2c: mlxcpld: Allow flexible polling time setting for I2C transactions
  i2c: pasemi: Set enable bit for Apple variant
  i2c: pasemi: Add Apple platform driver
  i2c: pasemi: Refactor _probe to use devm_*
  i2c: pasemi: Allow to configure bus frequency
  i2c: pasemi: Move common reset code to own function
  i2c: pasemi: Split pci driver to its own file
  i2c: pasemi: Split off common probing code
  i2c: pasemi: Remove usage of pci_dev
  i2c: pasemi: Use dev_name instead of port number
  ...

The ACPI_HANDLE() macro is a wrapper arond the ACPI_COMPANION()
macro and the ACPI handle produced by the former comes from the
ACPI device object produced by the latter, so it is way more
straightforward to evaluate the latter directly instead of passing
the handle produced by the former to acpi_bus_get_device().

Modify i2c_amd_probe() accordingly (no intentional functional impact).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Add PCI ID of SMBus controller on Intel Ice Lake PCH-N.

The device can be found on MacBookPro16,2 [1].

[1]: https://linux-hardware.org/?probe=f1c5cf0c43

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

PTR_ERR should access the value just tested by IS_ERR, otherwise
the wrong error code will be returned.

Fixes: 7b6da7fe7bba ("mailbox: pcc: Use PCC mailbox channel pointer instead of standard")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Pull driver core updates from Greg KH:
 "Here is the big set of driver core changes for 5.16-rc1.

  All of these have been in linux-next for a while now with no reported
  problems.

  Included in here are:

   - big update and cleanup of the sysfs abi documentation files and
     scripts from Mauro. We are almost at the place where we can
     properly check that the running kernel's sysfs abi is documented
     fully.

   - firmware loader updates

   - dyndbg updates

   - kernfs cleanups and fixes from Christoph

   - device property updates

   - component fix

   - other minor driver core cleanups and fixes"

* tag 'driver-core-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (122 commits)
  device property: Drop redundant NULL checks
  x86/build: Tuck away built-in firmware under FW_LOADER
  vmlinux.lds.h: wrap built-in firmware support under FW_LOADER
  firmware_loader: move struct builtin_fw to the only place used
  x86/microcode: Use the firmware_loader built-in API
  firmware_loader: remove old DECLARE_BUILTIN_FIRMWARE()
  firmware_loader: formalize built-in firmware API
  component: do not leave master devres group open after bind
  dyndbg: refine verbosity 1-4 summary-detail
  gpiolib: acpi: Replace custom code with device_match_acpi_handle()
  i2c: acpi: Replace custom function with device_match_acpi_handle()
  driver core: Provide device_match_acpi_handle() helper
  dyndbg: fix spurious vNpr_info change
  dyndbg: no vpr-info on empty queries
  dyndbg: vpr-info on remove-module complete, not starting
  device property: Add missed header in fwnode.h
  Documentation: dyndbg: Improve cli param examples
  dyndbg: Remove support for ddebug_query param
  dyndbg: make dyndbg a known cli param
  dyndbg: show module in vpr-info in dd-exec-queries
  ...

Pull virtio updates from Michael Tsirkin:
 "vhost and virtio fixes and features:

   - Hardening work by Jason

   - vdpa driver for Alibaba ENI

   - Performance tweaks for virtio blk

   - virtio rng rework using an internal buffer

   - mac/mtu programming for mlx5 vdpa

   - Misc fixes, cleanups"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (45 commits)
  vdpa/mlx5: Forward only packets with allowed MAC address
  vdpa/mlx5: Support configuration of MAC
  vdpa/mlx5: Fix clearing of VIRTIO_NET_F_MAC feature bit
  vdpa_sim_net: Enable user to set mac address and mtu
  vdpa: Enable user to set mac and mtu of vdpa device
  vdpa: Use kernel coding style for structure comments
  vdpa: Introduce query of device config layout
  vdpa: Introduce and use vdpa device get, set config helpers
  virtio-scsi: don't let virtio core to validate used buffer length
  virtio-blk: don't let virtio core to validate used length
  virtio-net: don't let virtio core to validate used length
  virtio_ring: validate used buffer length
  virtio_blk: correct types for status handling
  virtio_blk: allow 0 as num_request_queues
  i2c: virtio: Add support for zero-length requests
  virtio-blk: fixup coccinelle warnings
  virtio_ring: fix typos in vring_desc_extra
  virtio-pci: harden INTX interrupts
  virtio_pci: harden MSI-X interrupts
  virtio_config: introduce a new .enable_cbs method
  ...