It's hard for someone (like me) who's not following closely to know
what the suggested best practices are for error printing in DRM
drivers. Add some hints to the header file.
In general, my understanding is that:
* When possible we should be using a `struct drm_device` for logging
and recent patches have tried to make it more possible to access a
relevant `struct drm_device` in more places.
* For most cases when we don't have a `struct drm_device`, we no
longer bother with DRM-specific wrappers on the dev_...() functions
or pr_...() functions and just encourage drivers to use the normal
functions.
* For debug-level functions where we might want filtering based on a
category we'll still have DRM-specific wrappers, but we'll only
support passing a `struct drm_device`, not a `struct
device`. Presumably most of the cases where we want the filtering
are messages that happen while the system is in a normal running
state (AKA not during probe time) and we should have a `struct
drm_device` then. If we absolutely can't get a `struct drm_device`
then these functions begrudgingly accept NULL for the `struct
drm_device` and hopefully the awkwardness of having to manually pass
NULL will keep people from doing this unless absolutely necessary.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210921082757.RFC.1.Ibd82d98145615fa55f604947dc6a696cc82e8e43@changeid
While this shouldn't really be something that happens all that often, since
we're going to be using the drm_dbg_* log helpers in DRM helpers it's
technically possible that a driver could use an AUX adapter before it's
been associated with it's respective drm_device. While drivers should take
care to avoid this, there's likely going to be situations where it's
difficult to workaround. And since other logging helpers in the kernel tend
to be OK with NULL pointers (for instance, passing a NULL pointer to a "%s"
argument for a printk-like function in the kernel doesn't break anything),
we should do the same for ours.
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210423184309.207645-15-lyude@redhat.com
Reviewed-by: Dave Airlie <airlied@redhat.com>
Since we're about to move drm_dp_helper.c over to drm_dbg_*(), we'll want
to make sure that we can also add ratelimited versions of these macros in
order to retain some of the previous debugging output behavior we had.
However, as I was preparing to do this I noticed that the current
rate limited macros we have are kind of bogus. It looks like when I wrote
these, I didn't notice that we'd always be calling __ratelimit() even if
the debugging message we'd be printing would normally be filtered out due
to the relevant DRM debugging category being disabled.
So, let's fix this by making sure to check drm_debug_enabled() in our
ratelimited macros before calling __ratelimit(), and start using
drm_dev_printk() in order to print debugging messages since that will save
us from doing a redundant drm_debug_enabled() check. And while we're at it,
let's move the code for this into another macro that we can reuse for
defining new ratelimited DRM debug macros more easily.
v2:
* Make sure to use tabs where possible in __DRM_DEFINE_DBG_RATELIMITED()
Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: Robert Foss <robert.foss@linaro.org>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210326203807.105754-8-lyude@redhat.com
We have lots of these. And the cleanup code tends to be of dubious
quality. The biggest wrong pattern is that developers use devm_, which
ties the release action to the underlying struct device, whereas
all the userspace visible stuff attached to a drm_device can long
outlive that one (e.g. after a hotunplug while userspace has open
files and mmap'ed buffers). Give people what they want, but with more
correctness.
Mostly copied from devres.c, with types adjusted to fit drm_device and
a few simplifications - I didn't (yet) copy over everything. Since
the types don't match code sharing looked like a hopeless endeavour.
For now it's only super simplified, no groups, you can't remove
actions (but kfree exists, we'll need that soon). Plus all specific to
drm_device ofc, including the logging. Which I didn't bother to make
compile-time optional, since none of the other drm logging is compile
time optional either.
One tricky bit here is the chicken&egg between allocating your
drm_device structure and initiliazing it with drm_dev_init. For
perfect onion unwinding we'd need to have the action to kfree the
allocation registered before drm_dev_init registers any of its own
release handlers. But drm_dev_init doesn't know where exactly the
drm_device is emebedded into the overall structure, and by the time it
returns it'll all be too late. And forcing drivers to be able clean up
everything except the one kzalloc is silly.
Work around this by having a very special final_kfree pointer. This
also avoids troubles with the list head possibly disappearing from
underneath us when we release all resources attached to the
drm_device.
v2: Do all the kerneldoc at the end, to avoid lots of fairly pointless
shuffling while getting everything into shape.
v3: Add static to add/del_dr (Neil)
Move typo fix to the right patch (Neil)
v4: Enforce contract for drmm_add_final_kfree:
Use ksize() to check that the drm_device is indeed contained somewhere
in the final kfree(). Because we need that or the entire managed
release logic blows up in a pile of use-after-frees. Motivated by a
discussion with Laurent.
v5: Review from Laurent:
- %zu instead of casting size_t
- header guards
- sorting of includes
- guarding of data assignment if we didn't allocate it for a NULL
pointer
- delete spurious newline
- cast void* data parameter correctly in ->release call, no idea how
this even worked before
v6: Review from Sam
- Add the kerneldoc for the managed sub-struct back in, even if it
doesn't show up in the generated html somehow.
- Explain why __always_inline.
- Fix bisectability around the final kfree() in drm_dev_relase(). This
is just interim code which will disappear again.
- Some whitespace polish.
- Add debug output when drmm_add_action or drmm_kmalloc fail.
v7: My bisectability fix wasn't up to par as noticed by smatch.
v8: Remove unecessary {} around if else
v9: Use kstrdup_const, which requires kfree_const and introducing a free_dr()
helper (Thomas).
v10: kfree_const goes boom on the plain "kmalloc" assignment, somehow
we need to wrap that in kstrdup_const() too!! Also renumber revision
log, I somehow reset it midway thruh.
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Neil Armstrong <narmstrong@baylibre.com
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200324124540.3227396-1-daniel.vetter@ffwll.ch
Drop a few indirections, making the code simpler.
This also drops a RATELIMITED variant that is not in use.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200214175919.GA14492@ravnborg.org
We want to go over to the new lowercase ones, encourage that a bit
more.
v2: Remove the accidentally included hunk from some WIP branch this
was based on (Jani&Sam).
Cc: Jani Nikula <jani.nikula@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200214090428.2929833-1-daniel.vetter@ffwll.ch
Add new struct drm_device based WARN* macros. These are modeled after
the core kernel device based WARN* macros. These would be preferred
over the regular WARN* macros, where possible.
These macros include device information in the backtrace, so we know
what device the warnings originate from.
Knowing the device specific information in the backtrace would be
helpful in development all around.
Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Maxime Ripard <mripard@kernel.org>
Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Acked-by: Sean Paul <sean@poorly.run>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200115034455.17658-2-pankaj.laxminarayan.bharadiya@intel.com
Add new struct drm_device based logging macros modeled after the core
kernel device based logging macros. These would be preferred over the
drm printk and struct device based macros in drm code, where possible.
We have existing drm specific struct device based logging functions, but
they are too verbose to use for two main reasons:
* The names are unnecessarily long, for example DRM_DEV_DEBUG_KMS().
* The use of struct device over struct drm_device is too generic for
most users, leading to an extra dereference.
For example:
DRM_DEV_DEBUG_KMS(drm->dev, "Hello, world\n");
vs.
drm_dbg_kms(drm, "Hello, world\n");
It's a matter of taste, but the SHOUTING UPPERCASE has been argued to be
less readable than lowercase.
Some names are changed from old DRM names to be based on the core kernel
logging functions. For example, NOTE -> notice, ERROR -> err, DEBUG ->
dbg.
Due to the conflation of DRM_DEBUG and DRM_DEBUG_DRIVER macro use
(DRM_DEBUG is used widely in drivers though it's supposed to be a core
debugging category), they are named as drm_dbg_core and drm_dbg,
respectively.
The drm_err and _once/_ratelimited variants no longer include the
function name in order to be able to use the core device based logging
macros. Arguably this is not a significant change; error messages should
not be so common to be only distinguishable by the function name.
Ratelimited debug logging macros are to be added later.
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Sean Paul <sean@poorly.run>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191210123050.8799-1-jani.nikula@intel.com
drm_debug_enabled() is the way to check. __drm_debug is now reserved for
drm print code only. No functional changes.
v2: Rebase on move unlikely() to drm_debug_enabled()
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Eric Engestrom <eric@engestrom.ch>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Sean Paul <sean@poorly.run>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/840ff7292d1a39512bac2fcb1f45de9d50694bf1.1572258936.git.jani.nikula@intel.com
Add helper to check if a drm debug category is enabled. Convert drm core
to use it. No functional changes.
v2: Move unlikely() to drm_debug_enabled() (Eric)
v3: Keep unlikely() when combined with other conditions (Eric)
Cc: Eric Engestrom <eric@engestrom.ch>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Eric Engestrom <eric@engestrom.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191001140614.26909-1-jani.nikula@intel.com
There is little reason for the from/to logic, printing a subset of
the bits can be done by simply shifting/masking value if needed.
Also use for_each_set_bit().
Suggested-by: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Sean Paul <sean@poorly.run>
Link: http://patchwork.freedesktop.org/patch/msgid/20190923065814.4797-1-kraxel@redhat.com
A simple convienence function that returns a drm_printer which prints
using pr_err()
Changes since v1:
* Make __drm_printfn_err() more consistent with DRM_ERROR() - danvet
Cc: Juston Li <juston.li@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Harry Wentland <hwentlan@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190903204645.25487-6-lyude@redhat.com
drm_print.h requires <drm/drm.h> to fix build when macros are used.
Pull in the header file in drm_print.h so users do not have to do it.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Sean Paul <sean@poorly.run>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190609220757.10862-2-sam@ravnborg.org
The debugfs_regset32 is nice to use for reducing boilerplate in
dumping a bunch of regs in debugfs, but we also want to be able to
print to dmesg them at runtime for driver debugging. drm_printer lets
us format debugfs and the printk the same way.
v2: Add some kerneldoc for the function (requested by danvet)
Signed-off-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20190220210343.28157-1-eric@anholt.net
Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com> (v1)
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Add a puts function for the coredump printer to bypass printf()
for constant strings for a speed boost. Reorganize the
coredump printf callback to share as much code as possible.
v2: Try to reuse code between print and puts as suggested by
Chris Wilson
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
Add a puts() function to use seq_puts() to help speed up
up print time for constant strings.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
Add drm_puts() for a much faster path to print constant strings
into a drm_printer object with memcpy and friends. This can
have seconds off of really large outputs such as GPU dumps.
If the drm_printer object supports a custom puts function then
use that otherwise fall back to the slower legacy printf call.
v2: Add documentation for drm_puts() per Daniel Vetter
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
[robclark fix minor htmldocs warning]
Signed-off-by: Rob Clark <robdclark@gmail.com>
Add a drm printer suitable for use with the read callback for
devcoredump or other suitable buffer based output format that
isn't otherwise covered by seq_file.
v2: Add improved documentation per Daniel Vetter
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
This is something we've needed for a very long time now, as it makes
debugging issues with faulty MST hubs along with debugging issues
regarding us interfacing with hubs correctly vastly easier to debug.
Currently this can actually be done if you trace the i2c devices for DP
using ftrace but that's significantly less useful for a couple of
reasons:
- Tracing the i2c devices through ftrace means all of the traces are
going to contain a lot of "garbage" output that we're sending over the
i2c line. Most of this garbage comes from retrying transactions, DRM's
helper library adding extra transactions to work around bad hubs, etc.
- Having a user set up ftrace so that they can provide debugging
information is a lot more difficult then being able to say "just boot
with drm.debug=0x100"
- We can potentially expand upon this tracing in the future to print
debugging information in regards to other DP transactions like MST
sideband transactions
This is inspired by a patch Rob Clark sent to do this a long time back.
Neither of us could find the patch however, so we both assumed it would
probably just be easier to rewrite it anyway.
Cc: Rob Clark <robdclark@gmail.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180716154432.13433-1-lyude@redhat.com
These macros are similar to the DRM_<LEVEL> with the addition
of a struct device * to the arguments.
Convert the single drm_dev_printk function into 2 separate functions.
drm_dev_printk with a KERN_<LEVEL> * for generic use and drm_dev_dbg
for conditional masked use.
Remove the __func__ argument and use __builtin_return_address(0) to be
similar to the DRM_<LEVEL> macros uses.
Convert the DRM_DEV_<LEVEL> macros to remove now unnecessary arguments
and use a consistent style.
These macros are rarely used in the generic gpu/drm code so the code
size does not change much for a defconfig, but when more drivers are
enabled, there is ~4k savings.
Many of these macros have no existing use at all.
$ size -t drivers/gpu/drm/built-in.a | tail -1
1877530 44651 995 1923176 1d5868 (TOTALS)
$ size -t drivers/gpu/drm/built-in.a | tail -1
1877527 44651 995 1923173 1d5865 (TOTALS)
$ size -t drivers/gpu/drm/built-in.a | tail -1
17166750 2689238 108352 19964340 130a1b4 (TOTALS)
$ size -t drivers/gpu/drm/built-in.a | tail -1
17168888 2691734 108352 19968974 130b3ce (TOTALS)
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/e5c164946e15375ac71b69b75f296efdf0b76e6d.1521233717.git.joe@perches.com
drm_printk is used for both DRM_ERROR and DRM_DEBUG with unnecessary
arguments that can be removed by creating separate functins.
Create specific functions for these calls to reduce x86/64 defconfig
size by ~20k.
Modify the existing macros to use the specific calls.
new:
$ size -t drivers/gpu/drm/built-in.a | tail -1
1876562 44542 995 1922099 1d5433 (TOTALS)
old:
$ size -t drivers/gpu/drm/built-in.a | tail -1
1897565 44542 995 1943102 1da63e (TOTALS)
Miscellanea:
o intel_display requires a change to use the specific calls.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/016b5cb84cede20fd0f91ed6965421d99fd5f2ce.1520978414.git.joe@perches.com
It thinks we want to document the __printf(2,0) annotion. Not sure we
want to teach it about all possible gcc-only flags, hence why I opted
for the cheap trick of just moving it ahead of the kerneldoc.
This is only a problem for static inline functions, since for
non-inline function the kerneldoc is in the .c file, but the special
annotations are all in the header.
Cc'ing kernel-doc maintainers as fyi.
Cc: linux-doc@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171214203054.20141-3-daniel.vetter@ffwll.ch
Simple va_args equivalent to the existing drm_printf() for use with the
drm_printer.
v2: Fixup kerneldoc to match final parameter names.
v3: Turn it into a kerneldoc comment
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Rob Clark <robdclark@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171123084051.30203-1-chris@chris-wilson.co.uk
Bake in the conflict between the drm_print.h extraction and the
addition of DRM_DEBUG_LEASES since we lost it a few too many times.
Also fix a new use of drm_plane_helper_check_state in msm to follow
Ville's conversion in
commit a01cb8ba3f
Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date: Wed Nov 1 22:16:19 2017 +0200
drm: Move drm_plane_helper_check_state() into drm_atomic_helper.c
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Add drm_printf_indent() that adds tab indentation according to argument.
Indentation overflow is marked with an X.
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171107191348.17555-4-noralf@tronnes.org
sed -e 's/\( \* .*\)struct &\([_a-z]*\)/\1\&struct \2/' -i
Originally I wasnt a friend of this style because I thought a
line-break between the "&struct" and "foo" part would break it. But a
quick test shows that " * &struct \n * foo\n" works pefectly well with
current kernel-doc. So time to mass-apply these changes!
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1483044517-5770-6-git-send-email-daniel.vetter@ffwll.ch
kerneldoc expects the comment next to definitions, otherwise it can't
pick up exported vs. internal stuff.
This fixes a warning from the doc build done with:
$ make DOCBOOKS="" htmldocs
Fixes: d8187177b0 ("drm: add helper for printing to log or seq_file")
Cc: Rob Clark <robdclark@gmail.com>
Cc: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161114115825.22050-8-daniel.vetter@ffwll.ch
