[PATCH] docs: debugging: add more info about devcoredump

[Randy Dunlap]

Correct a few small things in the devcoredump synopsis and then add
the devcoredump APIs to it.

Fixes: a037699da0a1 ("docs: Add debugging section to process")
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Sebastian Fricke <sebastian.fricke@xxxxxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: linux-doc@xxxxxxxxxxxxxxx
Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: workflows@xxxxxxxxxxxxxxx
---
 Documentation/process/debugging/driver_development_debugging_guide.rst |   20 ++++++++--
 1 file changed, 16 insertions(+), 4 deletions(-)

--- linux-next-20241125.orig/Documentation/process/debugging/driver_development_debugging_guide.rst
+++ linux-next-20241125/Documentation/process/debugging/driver_development_debugging_guide.rst
@@ -207,17 +207,29 @@ resources, that can cause performance di
 device coredump
 ---------------
 
-Prerequisite: ``#include <linux/devcoredump.h>``
+Prerequisite: ``CONFIG_DEV_COREDUMP`` & ``#include <linux/devcoredump.h>``
 
 Provides the infrastructure for a driver to provide arbitrary data to userland.
 It is most often used in conjunction with udev or similar userland application
 to listen for kernel uevents, which indicate that the dump is ready. Udev has
 rules to copy that file somewhere for long-term storage and analysis, as by
-default, the data for the dump is automatically cleaned up after 5 minutes.
-That data is analyzed with driver-specific tools or GDB.
+default, the data for the dump is automatically cleaned up after a default
+5 minutes. That data is analyzed with driver-specific tools or GDB.
+
+A device coredump can be created with a vmalloc area, with read/free
+methods, or as a scatter/gather list.
 
 You can find an example implementation at:
 `drivers/media/platform/qcom/venus/core.c
-<https://elixir.bootlin.com/linux/v6.11.6/source/drivers/media/platform/qcom/venus/core.c#L30>`__
+<https://elixir.bootlin.com/linux/v6.11.6/source/drivers/media/platform/qcom/venus/core.c#L30>`__,
+in the Bluetooth HCI layer, in several wireless drivers, and in several
+DRM drivers.
+
+devcoredump interfaces
+~~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: include/linux/devcoredump.h
+
+.. kernel-doc:: drivers/base/devcoredump.c
 
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