kernel/linux.git/drivers/misc/mei/init.c, branch v6.18.22

mei: gsc: demote unexpected reset print

2025-09-18T16:29:33+00:00

Discrete graphic card can go to D3cold. On the exit from D3cold the link reset is performed. Driver did not expect such link reset and print warning. Print debug message for unexpected reset in discrete graphic case and remove infrastructure to print warning is some cases. Signed-off-by: Alexander Usyskin Signed-off-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20250918130435.3327400-6-alexander.usyskin@intel.com

mei: retry connect if interrupted by link reset

2025-09-18T16:29:33+00:00

When device is in D3cold the connect message will wake device and cause link reset. Link reset flow cleans all queues and wakes all waiters. Retry the connect flow if connect is failed and link reset is detected. Signed-off-by: Alexander Usyskin Signed-off-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20250918130435.3327400-4-alexander.usyskin@intel.com

mei: me: trigger link reset if hw ready is unexpected

2025-09-18T16:29:33+00:00

Driver can receive HW not ready interrupt unexpectedly. E.g. for cards that go donwn to D3cold. Trigger link reset in this case to synchronize driver and firmware state. No need to do that sync if driver is going down or interrupt is received before driver started initial link reset sequence. Introduce UNINITIALIZED device state to allow interrupt handler to ignore interrupts before first init. Signed-off-by: Alexander Usyskin Signed-off-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20250918130435.3327400-2-alexander.usyskin@intel.com

mei: hook mei_device on class device

2025-09-06T17:50:54+00:00

mei_device lifetime was managed by devm procedure of parent device. But such memory is freed on device_del. Mei_device object is used by client object that may be alive after parent device is removed. It may lead to use-after-free if discrete graphics driver unloads mei_gsc auxiliary device while user-space holds open handle to mei character device. Connect mei_device structure lifteme to mei class device lifetime by adding mei_device free to class device remove callback. Move exising parent device pointer to separate field in mei_device to avoid misuse. Allocate character device dynamically and allow to control its own lifetime as it may outlive mei_device structure while character device closes after parent device is removed from the system. Leave power management on parent device as we overwrite pci runtime pm procedure and user-space is expecting it there. Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/14201 Signed-off-by: Alexander Usyskin Link: https://lore.kernel.org/r/20250826125617.1166546-1-alexander.usyskin@intel.com Signed-off-by: Greg Kroah-Hartman

mei: me: emit error only if reset was unexpected

2023-10-18T08:01:34+00:00

GSC devices perform legal firmware initiated resets due to state transition that may appear as unexpected to the driver. Lower the log level for those devices to debug level and save the firmware status registers. When the device comes out of the reset it is possible to check whether the resets was due to a firmware error or an exception and only than produce a warning. Signed-off-by: Vitaly Lubart Signed-off-by: Tomas Winkler Link: https://lore.kernel.org/r/20231015080540.95922-1-tomas.winkler@intel.com Signed-off-by: Greg Kroah-Hartman

mei: obtain firmware version only on gsc.

2023-07-30T12:17:27+00:00

Modern GSC firmwares have both static and dynamic MKHI clients. Avoid expensive dynamic client call for firmware version retrieval, in case the firmware version is already retrieved from the fix address client in bus_fixup(). Signed-off-by: Alexander Usyskin Signed-off-by: Tomas Winkler Link: https://lore.kernel.org/r/20230716081043.3092690-3-tomas.winkler@intel.com Signed-off-by: Greg Kroah-Hartman

mei: log firmware status on hw_start failure.

2023-07-30T12:17:27+00:00

In order to extend debug information log firmware status details when waiting for firmware ready status fails. Signed-off-by: Alexander Usyskin Signed-off-by: Tomas Winkler Link: https://lore.kernel.org/r/20230716081043.3092690-1-tomas.winkler@intel.com Signed-off-by: Greg Kroah-Hartman

mei: drop ready bits check after start

2022-09-12T12:23:11+00:00

The check that hardware and host ready bits are set after start is redundant and may fail and disable driver if there is back-to-back link reset issued right after start. This happens during pxp mode transitions when firmware undergo reset. Remove these checks to eliminate such failures. Signed-off-by: Alexander Usyskin Signed-off-by: Tomas Winkler Reviewed-by: Daniele Ceraolo Spurio Signed-off-by: Daniele Ceraolo Spurio Link: https://patchwork.freedesktop.org/patch/msgid/20220907215113.1596567-14-tomas.winkler@intel.com Acked-by: Greg Kroah-Hartman Signed-off-by: Joonas Lahtinen

mei: gsc: setup gsc extended operational memory

2022-09-12T12:23:11+00:00

1. Retrieve extended operational memory physical pointers from the auxiliary device info. 2. Setup memory registers. 3. Notify firmware that the memory is ready by sending the memory ready command. 4. Disable PXP device if GSC is not in PXP mode. CC: Daniele Ceraolo Spurio Signed-off-by: Tomas Winkler Signed-off-by: Alexander Usyskin Reviewed-by: Daniele Ceraolo Spurio Signed-off-by: Daniele Ceraolo Spurio Link: https://patchwork.freedesktop.org/patch/msgid/20220907215113.1596567-12-tomas.winkler@intel.com Acked-by: Greg Kroah-Hartman Signed-off-by: Joonas Lahtinen Acked-by: Greg Kroah-Hartman Signed-off-by: Joonas Lahtinen

mei: extend timeouts on slow devices

2022-09-12T12:23:10+00:00

Parametrize operational timeouts in order to support slow firmware on some graphics devices. Signed-off-by: Alexander Usyskin Signed-off-by: Tomas Winkler Reviewed-by: Daniele Ceraolo Spurio Signed-off-by: Daniele Ceraolo Spurio Link: https://patchwork.freedesktop.org/patch/msgid/20220907215113.1596567-9-tomas.winkler@intel.com Acked-by: Greg Kroah-Hartman Signed-off-by: Joonas Lahtinen