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Diffstat (limited to 'Documentation/ABI/testing/sysfs-bus-mhi-devices-loopback')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-mhi-devices-loopback | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-mhi-devices-loopback b/Documentation/ABI/testing/sysfs-bus-mhi-devices-loopback new file mode 100644 index 000000000000..5435e65ef056 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-mhi-devices-loopback @@ -0,0 +1,49 @@ +What: /sys/bus/mhi/devices/mhi<N>_LOOPBACK/tre_size +Date: August 2026 +KernelVersion: 7.4 +Contact: mhi@lists.linux.dev +Description: + (RW) Size of each Transfer Ring Element (TRE) buffer in bytes + used for the loopback test. Valid range is 1 to the value + reported by max_tre_size. Default value is 32 bytes. + +What: /sys/bus/mhi/devices/mhi<N>_LOOPBACK/max_tre_size +Date: August 2026 +KernelVersion: 7.4 +Contact: mhi@lists.linux.dev +Description: + (RO) Maximum allowed Transfer Ring Element (TRE) size in bytes. + Reading this file returns the upper bound for the tre_size + attribute. + +What: /sys/bus/mhi/devices/mhi<N>_LOOPBACK/num_tre +Date: August 2026 +KernelVersion: 7.4 +Contact: mhi@lists.linux.dev +Description: + (RW) Number of Transfer Ring Elements (TREs) to use per + loopback test. Must be greater than zero and must not exceed + the value reported by max_num_tre. Default value is 1. + +What: /sys/bus/mhi/devices/mhi<N>_LOOPBACK/max_num_tre +Date: August 2026 +KernelVersion: 7.4 +Contact: mhi@lists.linux.dev +Description: + (RO) Maximum number of Transfer Ring Elements (TREs) currently + available on the channel ring. Reading this file returns the + upper bound for the num_tre attribute. + +What: /sys/bus/mhi/devices/mhi<N>_LOOPBACK/start +Date: August 2026 +KernelVersion: 7.4 +Contact: mhi@lists.linux.dev +Description: + (WO) Write any value to trigger a loopback test. The driver + sends random data to the endpoint using the configured tre_size + and num_tre parameters, waits for the endpoint to echo it back, + and verifies the received data matches what was sent. + + This is a blocking write that returns when the test completes + or times out after 5 seconds. The write returns an error code + if the test fails or times out. |