[nvidia-6.17-next] Add PCIe Hotplug Driver for CX7 on DGX Spark #271
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| for (i = 0; i < hp_dev->gpio_count; i++) { | ||
| app_ctx = &hp_dev->pins[i]; | ||
| if (app_ctx->desc) | ||
| gpiod_put(app_ctx->desc); |
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Is this the proper way to clean up these GPIO descriptors? It seems app_ctx->desc is set earlier via:
cx7_hp_enumerate_gpios()
gpio_device_get_desc()
Isn't the device's cleanup path already enough?
cx7_hp_put_gpio_device()
gpio_device_put(()
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You're absolutely right. Thanks for pointing this out.
gpio_device_get_desc() doesn't take a reference - it just returns a pointer into the GPIO device's internal structure. Since the GPIO device is managed via devm_add_action_or_reset() --> cx7_hp_put_gpio_device()--> gpio_device_put(), the manual gpiod_put() calls are unnecessary.
I've removed the gpiod_put() calls from both the error cleanup path and the remove function.
I also fixed the error cleanup path by adding a sysfs_remove: label to properly clean up the sysfs group when bus_register_notifier() fails, ensuring sysfs is cleaned up before pinctrl.
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| cx7_hp_pinctrl_remove(hp_dev); | ||
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| for (i = 0; i < hp_dev->gpio_count; i++) { |
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Same question as above regarding GPIO descriptor cleanup.
… DGX Spark
This driver manages PCIe link for NVIDIA ConnectX-7 (CX7) hot-plug/unplug
on DGX Spark systems with GB10 SoC. It disables the PCIe link
on cable removal and enables it on cable insertion.
Upstream-friendly improvements over 6.14 driver:
- Separated from MTK pinctrl driver into NVIDIA platform driver
- Configuration via ACPI (_CRS and _DSD), no hardcoded values
- Device-managed resources (devm_*) for automatic cleanup
- Thread-safe state management with locking
- Enhanced error handling and logging
- Uses standard Linux kernel APIs
The driver exposes a sysfs interface to emulate cable plug in/out:
echo 1 > /sys/devices/platform/MTKP0001:00/pcie_hotplug/debug_state # plug in
echo 0 > /sys/devices/platform/MTKP0001:00/pcie_hotplug/debug_state # plug out
It also provides a runtime enable/disable switch via sysfs:
echo 1 > /sys/devices/platform/MTKP0001:00/pcie_hotplug/hotplug_enabled # Enable
echo 0 > /sys/devices/platform/MTKP0001:00/pcie_hotplug/hotplug_enabled # Disable
This allows enabling/disabling hotplug functionality. Hotplug is disabled by default
and must be explicitly enabled via userspace.
It also implements uevent notifications for coordination with userspace:
* cable plug-in:
Report plug-in uevent (driver)
Enable PCIe link (driver)
Rescan CX7 devices (application)
* cable removal:
Report removal uevent (driver)
Remove CX7 devices (application)
Disable PCIe link (driver)
Signed-off-by: Vaibhav Vyas <vavyas@nvidia.com>
Signed-off-by: Scott Fudally <sfudally@nvidia.com>
Signed-off-by: Surabhi Chythanya Kumar <schythanyaku@nvidia.com>
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NVIDIA: SAUCE: MEDIATEK: platform: Add PCIe Hotplug Driver for CX7 on DGX Spark
This driver manages PCIe link for NVIDIA ConnectX-7 (CX7) hot-plug/unplug
on DGX Spark systems with GB10 SoC. It disables the PCIe link
on cable removal and enables it on cable insertion.
Upstream-friendly improvements over 6.14 driver:
The driver exposes a sysfs interface to emulate cable plug in/out:
echo 1 > /sys/devices/platform/MTKP0001:00/pcie_hotplug/debug_state # plug in
echo 0 > /sys/devices/platform/MTKP0001:00/pcie_hotplug/debug_state # plug out
It also provides a runtime enable/disable switch via sysfs:
echo 1 > /sys/devices/platform/MTKP0001:00/pcie_hotplug/hotplug_enabled # Enable
echo 0 > /sys/devices/platform/MTKP0001:00/pcie_hotplug/hotplug_enabled # Disable
This allows enabling/disabling hotplug functionality. Hotplug is disabled by default
and must be explicitly enabled via userspace.
It also implements uevent notifications for coordination with userspace:
cable plug-in:
Report plug-in uevent (driver)
Enable PCIe link (driver)
Rescan CX7 devices (application)
cable removal:
Report removal uevent (driver)
Remove CX7 devices (application)
Disable PCIe link (driver)
Signed-off-by: Vaibhav Vyas vavyas@nvidia.com
Signed-off-by: Scott Fudally sfudally@nvidia.com
Signed-off-by: Surabhi Chythanya Kumar schythanyaku@nvidia.com