xref: /linux/Documentation/ABI/testing/debugfs-dwc-pcie (revision bbfd5594756011167b8f8de9a00e0c946afda1e6)

What:		/sys/kernel/debug/dwc_pcie_<dev>/rasdes_debug/lane_detect
Date:		February 2025
Contact:	Shradha Todi <shradha.t@samsung.com>
Description:	(RW) Write the lane number to be checked for detection.	Read
		will return whether PHY indicates receiver detection on the
		selected lane. The default selected lane is Lane0.

What:		/sys/kernel/debug/dwc_pcie_<dev>/rasdes_debug/rx_valid
Date:		February 2025
Contact:	Shradha Todi <shradha.t@samsung.com>
Description:	(RW) Write the lane number to be checked as valid or invalid.
		Read will return the status of PIPE RXVALID signal of the
		selected lane. The default selected lane is Lane0.

What:		/sys/kernel/debug/dwc_pcie_<dev>/rasdes_err_inj/<error>
Date:		February 2025
Contact:	Shradha Todi <shradha.t@samsung.com>
Description:	The "rasdes_err_inj" is a directory which can be used to inject
		errors into the system. The possible errors that can be injected
		are:

		  1) tx_lcrc            - TLP LCRC error injection TX Path
		  2) b16_crc_dllp       - 16b CRC error injection of ACK/NAK DLLP
		  3) b16_crc_upd_fc     - 16b CRC error injection of Update-FC DLLP
		  4) tx_ecrc            - TLP ECRC error injection TX Path
		  5) fcrc_tlp           - TLP's FCRC error injection TX Path
		  6) parity_tsos        - Parity error of TSOS
		  7) parity_skpos       - Parity error on SKPOS
		  8) rx_lcrc            - LCRC error injection RX Path
		  9) rx_ecrc            - ECRC error injection RX Path
		  10) tlp_err_seq       - TLPs SEQ# error
		  11) ack_nak_dllp_seq  - DLLPS ACK/NAK SEQ# error
		  12) ack_nak_dllp      - ACK/NAK DLLPs transmission block
		  13) upd_fc_dllp       - UpdateFC DLLPs transmission block
		  14) nak_dllp          - Always transmission for NAK DLLP
		  15) inv_sync_hdr_sym  - Invert SYNC header
		  16) com_pad_ts1       - COM/PAD TS1 order set
		  17) com_pad_ts2       - COM/PAD TS2 order set
		  18) com_fts           - COM/FTS FTS order set
		  19) com_idl           - COM/IDL E-idle order set
		  20) end_edb           - END/EDB symbol
		  21) stp_sdp           - STP/SDP symbol
		  22) com_skp           - COM/SKP SKP order set
		  23) posted_tlp_hdr    - Posted TLP Header credit value control
		  24) non_post_tlp_hdr  - Non-Posted TLP Header credit value control
		  25) cmpl_tlp_hdr      - Completion TLP Header credit value control
		  26) posted_tlp_data   - Posted TLP Data credit value control
		  27) non_post_tlp_data - Non-Posted TLP Data credit value control
		  28) cmpl_tlp_data     - Completion TLP Data credit value control
		  29) duplicate_tlp     - Generates duplicate TLPs
		  30) nullified_tlp     - Generates Nullified TLPs

		(WO) Write to the attribute will prepare controller to inject
		the respective error in the next transmission of data.

		Parameter required to write will change in the following ways:

		- Errors 9 and 10 are sequence errors. The write command:

		    echo <count> <diff> > /sys/kernel/debug/dwc_pcie_<dev>/rasdes_err_inj/<error>

		    <count>
			    Number of errors to be injected
		    <diff>
			    The difference to add or subtract from natural
			    sequence number to generate sequence error.
			    Allowed range from -4095 to 4095

		- Errors 23 to 28 are credit value error insertions. The write
		  command:

		    echo <count> <diff> <vc> > /sys/kernel/debug/dwc_pcie_<dev>/rasdes_err_inj/<error>

		    <count>
			    Number of errors to be injected
		    <diff>
			    The difference to add or subtract from UpdateFC
			    credit value. Allowed range from -4095 to 4095
		    <vc>
			    Target VC number

		- All other errors. The write command:

		    echo <count> > /sys/kernel/debug/dwc_pcie_<dev>/rasdes_err_inj/<error>

		    <count>
			    Number of errors to be injected

What:		/sys/kernel/debug/dwc_pcie_<dev>/rasdes_event_counters/<event>/counter_enable
Date:		February 2025
Contact:	Shradha Todi <shradha.t@samsung.com>
Description:	The "rasdes_event_counters" is the directory which can be used
		to collect statistical data about the number of times a certain
		event has occurred in the controller. The list of possible
		events are:

		1) EBUF Overflow
		2) EBUF Underrun
		3) Decode Error
		4) Running Disparity Error
		5) SKP OS Parity Error
		6) SYNC Header Error
		7) Rx Valid De-assertion
		8) CTL SKP OS Parity Error
		9) 1st Retimer Parity Error
		10) 2nd Retimer Parity Error
		11) Margin CRC and Parity Error
		12) Detect EI Infer
		13) Receiver Error
		14) RX Recovery Req
		15) N_FTS Timeout
		16) Framing Error
		17) Deskew Error
		18) Framing Error In L0
		19) Deskew Uncompleted Error
		20) Bad TLP
		21) LCRC Error
		22) Bad DLLP
		23) Replay Number Rollover
		24) Replay Timeout
		25) Rx Nak DLLP
		26) Tx Nak DLLP
		27) Retry TLP
		28) FC Timeout
		29) Poisoned TLP
		30) ECRC Error
		31) Unsupported Request
		32) Completer Abort
		33) Completion Timeout
		34) EBUF SKP Add
		35) EBUF SKP Del

		(RW) Write 1 to enable the event counter and write 0 to disable
		the event counter. Read will return whether the counter is
		currently enabled or disabled. Counter is disabled by default.

What:		/sys/kernel/debug/dwc_pcie_<dev>/rasdes_event_counters/<event>/counter_value
Date:		February 2025
Contact:	Shradha Todi <shradha.t@samsung.com>
Description:	(RO) Read will return the current value of the event counter.
		To reset the counter, counter should be disabled first and then
		enabled back using the "counter_enable" attribute.

What:		/sys/kernel/debug/dwc_pcie_<dev>/rasdes_event_counters/<event>/lane_select
Date:		February 2025
Contact:	Shradha Todi <shradha.t@samsung.com>
Description:	(RW) Some lanes in the event list are lane specific events.
		These include events from 1 to 11, as well as, 34 and 35. Write
		the lane number for which you wish the counter to be enabled,
		disabled, or value dumped. Read will return the current
		selected lane number. Lane0 is selected by default.

What:		/sys/kernel/debug/dwc_pcie_<dev>/ltssm_status
Date:		February 2025
Contact:	Hans Zhang <18255117159@163.com>
Description:	(RO) Read will return the current PCIe LTSSM state in both
		string and raw value.