kernel/linux.git/drivers/thunderbolt/debugfs.c, branch v6.12.80

thunderbolt: Improve software receiver lane margining

2024-08-22T04:32:06+00:00

USB4 specification defines the metadata needed to perform software margining, as well as the necessary steps which include waiting for dwell time. - Add dwell_time attribute to set the wait time while performing margining and checking for link errors. - Add error_counter attribute to configure error counter prior to margining test. - Add voltage_time_offset attribute to set the voltage or time offset steps before performing the software margining test. - Perform software margining test for dwell duration, break if there are link errors, stop the clocks and provide results. Below is a minimalistic example how this can be used. Note these values are just examples. The exact values in practice depend on host specific capabilities and the type of measurement to be performed. # cd /sys/kernel/debug/thunderbolt/ROUTER/portX/margining/ # echo software > mode # echo 400 > dwell_time # echo 1 > run As usual the results attribute contains the results of a succesfull run. Signed-off-by: R Kannappan Co-developed-by: Rene Sapiens Signed-off-by: Rene Sapiens Co-developed-by: Aapo Vienamo Signed-off-by: Aapo Vienamo Signed-off-by: Mika Westerberg

thunderbolt: Add optional voltage offset range for receiver lane margining

2024-08-22T04:32:06+00:00

Add optional extended voltage offset range support for software and hardware margining as defined by the USB4 specification. If supported, it can be enabled like below: # cd /sys/kernel/debug/thunderbolt/ROUTER/portX/margining/ # echo Y > optional_voltage_offset Signed-off-by: Rene Sapiens Co-developed-by: R Kannappan Signed-off-by: R Kannappan Co-developed-by: Aapo Vienamo Signed-off-by: Aapo Vienamo Signed-off-by: Mika Westerberg

thunderbolt: Consolidate margining parameters into a structure

2024-08-22T04:32:06+00:00

Consolidate the hardware and software margining parameters into a single structure to reduce the number of parameters passed to the margining functions. Signed-off-by: Rene Sapiens Co-developed-by: Aapo Vienamo Signed-off-by: Aapo Vienamo Signed-off-by: Mika Westerberg

thunderbolt: Add missing usb4_port_sb_read() to usb4_port_sw_margin()

2024-08-22T04:32:06+00:00

Synchronize the operation completion by reading back the software margining operation completion metadata into margining->results. Signed-off-by: Aapo Vienamo Co-developed-by: R Kannappan Signed-off-by: R Kannappan Co-developed-by: Rene Sapiens Signed-off-by: Rene Sapiens Signed-off-by: Mika Westerberg

thunderbolt: Fix memory leaks in {port|retimer}_sb_regs_write()

2024-08-02T06:59:51+00:00

Add missing free_page() call for the memory allocated by validate_and_copy_from_user(). Fixes: 6d241fa00159 ("thunderbolt: Add sideband register access to debugfs") Signed-off-by: Aapo Vienamo Reviewed-by: Przemek Kitszel Signed-off-by: Mika Westerberg

thunderbolt: debugfs: Use FIELD_GET()

2024-06-19T04:30:20+00:00

Use the FIELD_GET() macro instead of open coding the masks and shifts. This makes the code more compact and improves readability as it avoids the need to wrap excessively long lines. Signed-off-by: Aapo Vienamo Reviewed-by: Andy Shevchenko Reviewed-by: Yehezkel Bernat Signed-off-by: Mika Westerberg

thunderbolt: Add receiver lane margining support for retimers

2024-06-17T09:47:12+00:00

Retimers support lane margining as well so make this available through debugfs in the same way as we do for the USB4 ports. When this is enabled we also expose retimers on the other side of the cable because typically margining is implemented only on direction towards the cable. However, for the retimers on the other side of the cable we do not allow NVM upgrade to avoid confusing the existing userspace (the same retimer may now appear twice with different name) and is probably not a good idea anyway. Signed-off-by: Mika Westerberg

thunderbolt: Make margining functions accept target and retimer index

2024-06-17T09:47:12+00:00

In order to add lane margining support for retimers make the margining functions take sideband target and retimer index as parameters. This makes it possible to access both router and retimer sideband using the same functions. Signed-off-by: Mika Westerberg

thunderbolt: Split out margining from USB4 port

2024-06-17T09:47:11+00:00

We are going to expand lane margining support for retimers too so split out the generic margining functionality out of being specific to USB4 ports. Signed-off-by: Mika Westerberg

thunderbolt: Add sideband register access to debugfs

2024-06-17T09:47:11+00:00

This makes it possible to read and write USB4 port and retimer sideband registers through debugfs which is useful for debugging and manufacturing purposes. We add "sb_regs" debugfs attribute under each USB4 port and retimer that is used to access the sideband. Signed-off-by: Mika Westerberg