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Date:   Thu, 22 Apr 2021 10:18:12 +0200
From:   Daniel Vetter <daniel@ffwll.ch>
To:     Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc:     Daniel Vetter <daniel.vetter@ffwll.ch>,
        intel-gfx <intel-gfx@lists.freedesktop.org>,
        Stephen Rothwell <sfr@canb.auug.org.au>,
        DRI <dri-devel@lists.freedesktop.org>,
        Dave Airlie <airlied@linux.ie>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] drm/i915: Fix docbook descriptions for i915_cmd_parser
Message-ID: <YIExRAHQvZmgL5S+@phenom.ffwll.local>
Mail-Followup-To: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        intel-gfx <intel-gfx@lists.freedesktop.org>,
        Stephen Rothwell <sfr@canb.auug.org.au>,
        DRI <dri-devel@lists.freedesktop.org>,
        Dave Airlie <airlied@linux.ie>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
References: <20210421120353.544518-1-maarten.lankhorst@linux.intel.com>
 <CAKMK7uFpoY7YMEMbftjq+P5XHR6L+F0KwFtbK7CtuUFy7HsLkQ@mail.gmail.com>
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On Wed, Apr 21, 2021 at 04:39:10PM +0200, Maarten Lankhorst wrote:
> Op 21-04-2021 om 16:32 schreef Daniel Vetter:
> > On Wed, Apr 21, 2021 at 2:03 PM Maarten Lankhorst
> > <maarten.lankhorst@linux.intel.com> wrote:
> >> Fixes the following htmldocs warnings:
> >> drivers/gpu/drm/i915/i915_cmd_parser.c:1420: warning: Excess function parameter 'trampoline' description in 'intel_engine_cmd_parser'
> >> drivers/gpu/drm/i915/i915_cmd_parser.c:1420: warning: Function parameter or member 'jump_whitelist' not described in 'intel_engine_cmd_parser'
> >> drivers/gpu/drm/i915/i915_cmd_parser.c:1420: warning: Function parameter or member 'shadow_map' not described in 'intel_engine_cmd_parser'
> >> drivers/gpu/drm/i915/i915_cmd_parser.c:1420: warning: Function parameter or member 'batch_map' not described in 'intel_engine_cmd_parser'
> >> drivers/gpu/drm/i915/i915_cmd_parser.c:1420: warning: Excess function parameter 'trampoline' description in 'intel_engine_cmd_parser'
> >>
> >> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
> >> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> >> ---
> >>  drivers/gpu/drm/i915/i915_cmd_parser.c | 16 +++++++++++++++-
> >>  1 file changed, 15 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c
> >> index e6f1e93abbbb..afb9b7516999 100644
> >> --- a/drivers/gpu/drm/i915/i915_cmd_parser.c
> >> +++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
> >> @@ -1369,6 +1369,18 @@ static int check_bbstart(u32 *cmd, u32 offset, u32 length,
> >>         return 0;
> >>  }
> >>
> >> +/**
> >> + * intel_engine_cmd_parser_alloc_jump_whitelist() - preallocate jump whitelist for intel_engine_cmd_parser()
> >> + * @batch_length: length of the commands in batch_obj
> >> + * @trampoline: Whether jump trampolines are used.
> >> + *
> >> + * Preallocates a jump whitelist for parsing the cmd buffer in intel_engine_cmd_parser().
> >> + * This has to be preallocated, because the command parser runs in signaling context,
> >> + * and may not allocate any memory.
> >> + *
> >> + * Return: NULL or pointer to a jump whitelist, or ERR_PTR() on failure. Use
> >> + * IS_ERR() to check for errors. Must bre freed() with kfree().
> > IS_ERR_OR_NULL or needs an actual bugfix in the code since we're not
> > consistent. Also s/bre/be/
> We're sort of consistent, NULL is a valid return code. IS_ERR is only on faliure. :)

Maybe explain that and then Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Cheers, Daniel

> > -Daniel
> >
> >> + */
> >>  unsigned long *intel_engine_cmd_parser_alloc_jump_whitelist(u32 batch_length,
> >>                                                             bool trampoline)
> >>  {
> >> @@ -1401,7 +1413,9 @@ unsigned long *intel_engine_cmd_parser_alloc_jump_whitelist(u32 batch_length,
> >>   * @batch_offset: byte offset in the batch at which execution starts
> >>   * @batch_length: length of the commands in batch_obj
> >>   * @shadow: validated copy of the batch buffer in question
> >> - * @trampoline: whether to emit a conditional trampoline at the end of the batch
> >> + * @jump_whitelist: buffer preallocated with intel_engine_cmd_parser_alloc_jump_whitelist()
> >> + * @shadow_map: mapping to @shadow vma
> >> + * @batch_map: mapping to @batch vma
> >>   *
> >>   * Parses the specified batch buffer looking for privilege violations as
> >>   * described in the overview.
> >> --
> >> 2.31.0
> >>
> >
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch