ata: libata-scsi: fix ata_dsm_trim_pages() kernel-docgrafted

make htmldocs fails with:

  Documentation/driver-api/libata:604: ./drivers/ata/libata-scsi.c:2301:
  ERROR: Unexpected indentation. [docutils]

The Return: section of ata_dsm_trim_pages() ends its first sentence with
a colon and continues with an indented bullet list. reStructuredText
requires a blank line before an indented block, so docutils chokes on
the list.

Simply adding the missing blank line does not work either: Return: is a
kernel-doc "special section", which is terminated by the first blank
line, so the bullet list would end up in the Description section,
detached from the sentence introducing it.

Spell the two bounds out as prose instead, so that the Return: section
stays self-contained. Documentation-only change.

Fixes: e64e6b5dc867 ("ata: libata-scsi: scale DSM TRIM payload by MAX PAGES PER DSM COMMAND")
Reported-by: Thomas Huth <thuth@redhat.com>
Closes: https://lore.kernel.org/linux-ide/b0a0b8e8-cc4f-4c7b-8bc5-fee0712d405a@redhat.com/
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Link: https://lore.kernel.org/r/20260916130031.29990-2-cassel@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>

1 files changed, 105 insertions, 0 deletions

diff --git a/Documentation/gpu/amdgpu/debugging.rst b/Documentation/gpu/amdgpu/debugging.rst
new file mode 100644
index 000000000..ac914d524
--- /dev/null
+++ b/Documentation/gpu/amdgpu/debugging.rst
@@ -0,0 +1,105 @@
+===============
+ GPU Debugging
+===============
+
+General Debugging Options
+=========================
+
+The DebugFS section provides documentation on a number files to aid in debugging
+issues on the GPU.
+
+
+GPUVM Debugging
+===============
+
+To aid in debugging GPU virtual memory related problems, the driver supports a
+number of options module parameters:
+
+`vm_fault_stop` - If non-0, halt the GPU memory controller on a GPU page fault.
+
+`vm_update_mode` - If non-0, use the CPU to update GPU page tables rather than
+the GPU.
+
+
+Decoding a GPUVM Page Fault
+===========================
+
+If you see a GPU page fault in the kernel log, you can decode it to figure
+out what is going wrong in your application.  A page fault in your kernel
+log may look something like this:
+
+::
+
+ [gfxhub0] no-retry page fault (src_id:0 ring:24 vmid:3 pasid:32777, for process glxinfo pid 2424 thread glxinfo:cs0 pid 2425)
+   in page starting at address 0x0000800102800000 from IH client 0x1b (UTCL2)
+ VM_L2_PROTECTION_FAULT_STATUS:0x00301030
+ 	Faulty UTCL2 client ID: TCP (0x8)
+ 	MORE_FAULTS: 0x0
+ 	WALKER_ERROR: 0x0
+ 	PERMISSION_FAULTS: 0x3
+ 	MAPPING_ERROR: 0x0
+ 	RW: 0x0
+
+First you have the memory hub, gfxhub and mmhub.  gfxhub is the memory
+hub used for graphics, compute, and sdma on some chips.  mmhub is the
+memory hub used for multi-media and sdma on some chips.
+
+Next you have the vmid and pasid.  If the vmid is 0, this fault was likely
+caused by the kernel driver or firmware.  If the vmid is non-0, it is generally
+a fault in a user application.  The pasid is used to link a vmid to a system
+process id.  If the process is active when the fault happens, the process
+information will be printed.
+
+The GPU virtual address that caused the fault comes next.
+
+The client ID indicates the GPU block that caused the fault.
+Some common client IDs:
+
+- CB/DB: The color/depth backend of the graphics pipe
+- CPF: Command Processor Frontend
+- CPC: Command Processor Compute
+- CPG: Command Processor Graphics
+- TCP/SQC/SQG: Shaders
+- SDMA: SDMA engines
+- VCN: Video encode/decode engines
+- JPEG: JPEG engines
+
+PERMISSION_FAULTS describe what faults were encountered:
+
+- bit 0: the PTE was not valid
+- bit 1: the PTE read bit was not set
+- bit 2: the PTE write bit was not set
+- bit 3: the PTE execute bit was not set
+
+Finally, RW, indicates whether the access was a read (0) or a write (1).
+
+In the example above, a shader (cliend id = TCP) generated a read (RW = 0x0) to
+an invalid page (PERMISSION_FAULTS = 0x3) at GPU virtual address
+0x0000800102800000.  The user can then inspect their shader code and resource
+descriptor state to determine what caused the GPU page fault.
+
+UMR
+===
+
+`umr <https://gitlab.freedesktop.org/tomstdenis/umr>`_ is a general purpose
+GPU debugging and diagnostics tool.  Please see the umr
+`documentation <https://umr.readthedocs.io/en/main/>`_ for more information
+about its capabilities.
+
+Debugging backlight brightness
+==============================
+Default backlight brightness is intended to be set via the policy advertised
+by the firmware.  Firmware will often provide different defaults for AC or DC.
+Furthermore, some userspace software will save backlight brightness during
+the previous boot and attempt to restore it.
+
+Some firmware also has support for a feature called "Custom Backlight Curves"
+where an input value for brightness is mapped along a linearly interpolated
+curve of brightness values that better match display characteristics.
+
+In the event of problems happening with backlight, there is a trace event
+that can be enabled at bootup to log every brightness change request.
+This can help isolate where the problem is. To enable the trace event add
+the following to the kernel command line:
+
+  tp_printk trace_event=amdgpu_dm:amdgpu_dm_brightness:mod:amdgpu trace_buf_size=1M