[PATCH (set 1) 00/20] Rid W=1 warnings from GPU

[PATCH (set 1) 00/20] Rid W=1 warnings from GPU

[Lee Jones]

This set is part of a larger effort attempting to clean-up W=1
kernel builds, which are currently overwhelmingly riddled with
niggly little warnings.

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: amd-gfx@lists.freedesktop.org
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Danilo Krummrich <dakr@redhat.com>
Cc: David Airlie <airlied@gmail.com>
Cc: dri-devel@lists.freedesktop.org
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Gourav Samaiya <gsamaiya@nvidia.com>
Cc: Hawking Zhang <Hawking.Zhang@amd.com>
Cc: Hyun Kwon <hyun.kwon@xilinx.com>
Cc: Jerome Glisse <glisse@freedesktop.org>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: linaro-mm-sig@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-media@vger.kernel.org
Cc: linux-tegra@vger.kernel.org
Cc: Luben Tuikov <luben.tuikov@amd.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: "Maíra Canal" <mairacanal@riseup.net>
Cc: Mario Limonciello <mario.limonciello@amd.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Mikko Perttunen <mperttunen@nvidia.com>
Cc: nouveau@lists.freedesktop.org
Cc: NXP Linux Team <linux-imx@nxp.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shashank Sharma <shashank.sharma@amd.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Stanley Yang <Stanley.Yang@amd.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>

Lee Jones (20):
  drm/xlnx/zynqmp_disp: Use correct kerneldoc formatting in zynqmp_disp
  drm/nouveau/nvkm/subdev/acr/lsfw: Remove unused variable 'loc'
  drm/nouveau/nvkm/subdev/bios/init: Demote a bunch of kernel-doc abuses
  drm/nouveau/nvkm/subdev/volt/gk20a: Demote kerneldoc abuses
  drm/nouveau/nvkm/engine/gr/gf100: Demote kerneldoc abuse
  drm/nouveau/dispnv04/crtc: Demote kerneldoc abuses
  drm/radeon/radeon_ttm: Remove unused variable 'rbo' from
    radeon_bo_move()
  drm/amd/amdgpu/sdma_v6_0: Demote a bunch of half-completed function
    headers
  drm/tests/drm_kunit_helpers: Place correct function name in the
    comment header
  drm/scheduler/sched_main: Provide short description of missing param
    'result'
  drm/amd/amdgpu/amdgpu_doorbell_mgr: Correct misdocumented param
    'doorbell_index'
  drm/amd/amdgpu/amdgpu_device: Provide suitable description for param
    'xcc_id'
  drm/tests/drm_kunit_helpers: Correct possible double-entry typo in
    'ddrm_kunit_helper_acquire_ctx_alloc'
  drm/imx/ipuv3/imx-ldb: Increase buffer size to ensure all possible
    values can be stored
  drm/tegra/hub: Increase buffer size to ensure all possible values can
    be stored
  drm/drm_connector: Provide short description of param
    'supported_colorspaces'
  drm/amd/amdgpu/amdgpu_ras: Increase buffer size to account for all
    possible values
  drm/drm_gpuva_mgr: Remove set but unused variable 'prev'
  drm/amd/amdgpu/amdgpu_sdma: Increase buffer size to account for all
    possible values
  drm/amd/amdgpu/imu_v11_0: Increase buffer size to ensure all possible
    values can be stored

 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c    |   1 +
 .../gpu/drm/amd/amdgpu/amdgpu_doorbell_mgr.c  |   2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h       |   2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_sdma.c      |   2 +-
 drivers/gpu/drm/amd/amdgpu/imu_v11_0.c        |   2 +-
 drivers/gpu/drm/amd/amdgpu/sdma_v6_0.c        |   8 +-
 drivers/gpu/drm/drm_connector.c               |   2 +
 drivers/gpu/drm/drm_gpuva_mgr.c               |  10 +-
 drivers/gpu/drm/imx/ipuv3/imx-ldb.c           |   2 +-
 drivers/gpu/drm/nouveau/dispnv04/crtc.c       |   4 +-
 .../gpu/drm/nouveau/nvkm/engine/gr/gf100.c    |   2 +-
 .../gpu/drm/nouveau/nvkm/subdev/acr/lsfw.c    |   3 +-
 .../gpu/drm/nouveau/nvkm/subdev/bios/init.c   | 136 +++++++++---------
 .../gpu/drm/nouveau/nvkm/subdev/volt/gk20a.c  |   4 +-
 drivers/gpu/drm/radeon/radeon_ttm.c           |   2 -
 drivers/gpu/drm/scheduler/sched_main.c        |   1 +
 drivers/gpu/drm/tegra/hub.c                   |   2 +-
 drivers/gpu/drm/tests/drm_kunit_helpers.c     |   2 +-
 drivers/gpu/drm/xlnx/zynqmp_disp.c            |   6 +-
 19 files changed, 96 insertions(+), 97 deletions(-)

-- 
2.42.0.rc1.204.g551eb34607-goog

[PATCH 15/20] drm/tegra/hub: Increase buffer size to ensure all possible values can be stored

[Lee Jones]

When converting from int to string, we must allow for up to 10-chars (2147483647).

Fixes the following W=1 kernel build warning(s):

 drivers/gpu/drm/tegra/hub.c: In function ‘tegra_display_hub_probe’:
 drivers/gpu/drm/tegra/hub.c:1106:47: warning: ‘%u’ directive output may be truncated writing between 1 and 10 bytes into a region of size 4 [-Wformat-truncation=]
 drivers/gpu/drm/tegra/hub.c:1106:42: note: directive argument in the range [0, 4294967294]
 drivers/gpu/drm/tegra/hub.c:1106:17: note: ‘snprintf’ output between 6 and 15 bytes into a destination of size 8

Signed-off-by: Lee Jones <lee@kernel.org>
---
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Mikko Perttunen <mperttunen@nvidia.com>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-tegra@vger.kernel.org
---
 drivers/gpu/drm/tegra/hub.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/tegra/hub.c b/drivers/gpu/drm/tegra/hub.c
index 1af5f8318d914..f21e57e8599ee 100644
--- a/drivers/gpu/drm/tegra/hub.c
+++ b/drivers/gpu/drm/tegra/hub.c
@@ -1101,7 +1101,7 @@ static int tegra_display_hub_probe(struct platform_device *pdev)
 
 	for (i = 0; i < hub->soc->num_wgrps; i++) {
 		struct tegra_windowgroup *wgrp = &hub->wgrps[i];
-		char id[8];
+		char id[16];
 
 		snprintf(id, sizeof(id), "wgrp%u", i);
 		mutex_init(&wgrp->lock);
-- 
2.42.0.rc1.204.g551eb34607-goog

Re: [PATCH (set 1) 00/20] Rid W=1 warnings from GPU

[Maxime Ripard]

On Thu, 24 Aug 2023 08:36:45 +0100, Lee Jones wrote:
> This set is part of a larger effort attempting to clean-up W=1
> kernel builds, which are currently overwhelmingly riddled with
> niggly little warnings.
> 
> Cc: Alex Deucher <alexander.deucher@amd.com>
> Cc: amd-gfx@lists.freedesktop.org
> Cc: Ben Skeggs <bskeggs@redhat.com>
> Cc: "Christian König" <christian.koenig@amd.com>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Cc: Danilo Krummrich <dakr@redhat.com>
> Cc: David Airlie <airlied@gmail.com>
> Cc: dri-devel@lists.freedesktop.org
> Cc: Fabio Estevam <festevam@gmail.com>
> Cc: Gourav Samaiya <gsamaiya@nvidia.com>
> Cc: Hawking Zhang <Hawking.Zhang@amd.com>
> Cc: Hyun Kwon <hyun.kwon@xilinx.com>
> Cc: Jerome Glisse <glisse@freedesktop.org>
> Cc: Jonathan Hunter <jonathanh@nvidia.com>
> Cc: Karol Herbst <kherbst@redhat.com>
> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Cc: linaro-mm-sig@lists.linaro.org
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-media@vger.kernel.org
> Cc: linux-tegra@vger.kernel.org
> Cc: Luben Tuikov <luben.tuikov@amd.com>
> Cc: Lyude Paul <lyude@redhat.com>
> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> Cc: "Maíra Canal" <mairacanal@riseup.net>
> Cc: Mario Limonciello <mario.limonciello@amd.com>
> Cc: Maxime Ripard <mripard@kernel.org>
> Cc: Michal Simek <michal.simek@xilinx.com>
> Cc: Mikko Perttunen <mperttunen@nvidia.com>
> Cc: nouveau@lists.freedesktop.org
> Cc: NXP Linux Team <linux-imx@nxp.com>
> Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
> Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
> Cc: Philipp Zabel <p.zabel@pengutronix.de>
> Cc: Sascha Hauer <s.hauer@pengutronix.de>
> Cc: Shashank Sharma <shashank.sharma@amd.com>
> Cc: Shawn Guo <shawnguo@kernel.org>
> Cc: Stanley Yang <Stanley.Yang@amd.com>
> Cc: Sumit Semwal <sumit.semwal@linaro.org>
> Cc: Thierry Reding <thierry.reding@gmail.com>
> Cc: Thomas Zimmermann <tzimmermann@suse.de>
> 
> [...]

Applied to drm/drm-misc (drm-misc-fixes).

Thanks!
Maxime

Re: [PATCH (set 1) 00/20] Rid W=1 warnings from GPU

[Maxime Ripard]

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Hi,

On Thu, Aug 24, 2023 at 10:59:54AM +0200, Maxime Ripard wrote:
> On Thu, 24 Aug 2023 08:36:45 +0100, Lee Jones wrote:
> > This set is part of a larger effort attempting to clean-up W=1
> > kernel builds, which are currently overwhelmingly riddled with
> > niggly little warnings.
> > 
> > Cc: Alex Deucher <alexander.deucher@amd.com>
> > Cc: amd-gfx@lists.freedesktop.org
> > Cc: Ben Skeggs <bskeggs@redhat.com>
> > Cc: "Christian König" <christian.koenig@amd.com>
> > Cc: Daniel Vetter <daniel@ffwll.ch>
> > Cc: Danilo Krummrich <dakr@redhat.com>
> > Cc: David Airlie <airlied@gmail.com>
> > Cc: dri-devel@lists.freedesktop.org
> > Cc: Fabio Estevam <festevam@gmail.com>
> > Cc: Gourav Samaiya <gsamaiya@nvidia.com>
> > Cc: Hawking Zhang <Hawking.Zhang@amd.com>
> > Cc: Hyun Kwon <hyun.kwon@xilinx.com>
> > Cc: Jerome Glisse <glisse@freedesktop.org>
> > Cc: Jonathan Hunter <jonathanh@nvidia.com>
> > Cc: Karol Herbst <kherbst@redhat.com>
> > Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > Cc: linaro-mm-sig@lists.linaro.org
> > Cc: linux-arm-kernel@lists.infradead.org
> > Cc: linux-media@vger.kernel.org
> > Cc: linux-tegra@vger.kernel.org
> > Cc: Luben Tuikov <luben.tuikov@amd.com>
> > Cc: Lyude Paul <lyude@redhat.com>
> > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> > Cc: "Maíra Canal" <mairacanal@riseup.net>
> > Cc: Mario Limonciello <mario.limonciello@amd.com>
> > Cc: Maxime Ripard <mripard@kernel.org>
> > Cc: Michal Simek <michal.simek@xilinx.com>
> > Cc: Mikko Perttunen <mperttunen@nvidia.com>
> > Cc: nouveau@lists.freedesktop.org
> > Cc: NXP Linux Team <linux-imx@nxp.com>
> > Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
> > Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
> > Cc: Philipp Zabel <p.zabel@pengutronix.de>
> > Cc: Sascha Hauer <s.hauer@pengutronix.de>
> > Cc: Shashank Sharma <shashank.sharma@amd.com>
> > Cc: Shawn Guo <shawnguo@kernel.org>
> > Cc: Stanley Yang <Stanley.Yang@amd.com>
> > Cc: Sumit Semwal <sumit.semwal@linaro.org>
> > Cc: Thierry Reding <thierry.reding@gmail.com>
> > Cc: Thomas Zimmermann <tzimmermann@suse.de>
> > 
> > [...]
> 
> Applied to drm/drm-misc (drm-misc-fixes).

I got confused with b4 usage, but that wasn't actually applied. Only the
three patches I explicitly mentioned were, sorry for the confusion.

Maxime

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Re: [PATCH (set 1) 00/20] Rid W=1 warnings from GPU

[Jani Nikula]

On Thu, 24 Aug 2023, Lee Jones <lee@kernel.org> wrote:
> This set is part of a larger effort attempting to clean-up W=1
> kernel builds, which are currently overwhelmingly riddled with
> niggly little warnings.

The next question is, how do we keep it W=1 clean going forward?

Most people don't use W=1 because it's too noisy, so it's a bit of a
catch-22.

In i915, we enable a lot of W=1 warnings using subdir-ccflags-y in our
Makefile. For CI/developer use we also enable kernel-doc warnings by
default.

Should we start enabling some of those warning flags in drm/Makefile to
to keep the entire subsystem warning free?


BR,
Jani.


-- 
Jani Nikula, Intel Open Source Graphics Center

Re: [PATCH (set 1) 00/20] Rid W=1 warnings from GPU

[Maxime Ripard]

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On Thu, Aug 24, 2023 at 12:03:20PM +0300, Jani Nikula wrote:
> On Thu, 24 Aug 2023, Lee Jones <lee@kernel.org> wrote:
> > This set is part of a larger effort attempting to clean-up W=1
> > kernel builds, which are currently overwhelmingly riddled with
> > niggly little warnings.
> 
> The next question is, how do we keep it W=1 clean going forward?
> 
> Most people don't use W=1 because it's too noisy, so it's a bit of a
> catch-22.
> 
> In i915, we enable a lot of W=1 warnings using subdir-ccflags-y in our
> Makefile. For CI/developer use we also enable kernel-doc warnings by
> default.
> 
> Should we start enabling some of those warning flags in drm/Makefile to
> to keep the entire subsystem warning free?

I think that's a good idea. At least the documentation fixes I just
merged could have been easily caught before submission.

Maxime

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Re: [PATCH 15/20] drm/tegra/hub: Increase buffer size to ensure all possible values can be stored

[Thierry Reding]

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On Thu, Aug 24, 2023 at 08:37:00AM +0100, Lee Jones wrote:
> When converting from int to string, we must allow for up to 10-chars (2147483647).
> 
> Fixes the following W=1 kernel build warning(s):
> 
>  drivers/gpu/drm/tegra/hub.c: In function ‘tegra_display_hub_probe’:
>  drivers/gpu/drm/tegra/hub.c:1106:47: warning: ‘%u’ directive output may be truncated writing between 1 and 10 bytes into a region of size 4 [-Wformat-truncation=]
>  drivers/gpu/drm/tegra/hub.c:1106:42: note: directive argument in the range [0, 4294967294]
>  drivers/gpu/drm/tegra/hub.c:1106:17: note: ‘snprintf’ output between 6 and 15 bytes into a destination of size 8

I wish there was (perhaps there is?) a better way to annotate that i
will always be within a given range. In practice this is always going to
be smaller than 10 and even in future hardware I wouldn't expect this to
ever exceed anything like 32 or 64, so 8 characters is already generous.

Thierry

> 
> Signed-off-by: Lee Jones <lee@kernel.org>
> ---
> Cc: Thierry Reding <thierry.reding@gmail.com>
> Cc: Mikko Perttunen <mperttunen@nvidia.com>
> Cc: David Airlie <airlied@gmail.com>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Cc: Jonathan Hunter <jonathanh@nvidia.com>
> Cc: Philipp Zabel <p.zabel@pengutronix.de>
> Cc: dri-devel@lists.freedesktop.org
> Cc: linux-tegra@vger.kernel.org
> ---
>  drivers/gpu/drm/tegra/hub.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/tegra/hub.c b/drivers/gpu/drm/tegra/hub.c
> index 1af5f8318d914..f21e57e8599ee 100644
> --- a/drivers/gpu/drm/tegra/hub.c
> +++ b/drivers/gpu/drm/tegra/hub.c
> @@ -1101,7 +1101,7 @@ static int tegra_display_hub_probe(struct platform_device *pdev)
>  
>  	for (i = 0; i < hub->soc->num_wgrps; i++) {
>  		struct tegra_windowgroup *wgrp = &hub->wgrps[i];
> -		char id[8];
> +		char id[16];
>  
>  		snprintf(id, sizeof(id), "wgrp%u", i);
>  		mutex_init(&wgrp->lock);
> -- 
> 2.42.0.rc1.204.g551eb34607-goog
> 

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Re: [PATCH 15/20] drm/tegra/hub: Increase buffer size to ensure all possible values can be stored

[Jani Nikula]

On Thu, 24 Aug 2023, Thierry Reding <thierry.reding@gmail.com> wrote:
> On Thu, Aug 24, 2023 at 08:37:00AM +0100, Lee Jones wrote:
>> When converting from int to string, we must allow for up to 10-chars (2147483647).
>> 
>> Fixes the following W=1 kernel build warning(s):
>> 
>>  drivers/gpu/drm/tegra/hub.c: In function ‘tegra_display_hub_probe’:
>>  drivers/gpu/drm/tegra/hub.c:1106:47: warning: ‘%u’ directive output may be truncated writing between 1 and 10 bytes into a region of size 4 [-Wformat-truncation=]
>>  drivers/gpu/drm/tegra/hub.c:1106:42: note: directive argument in the range [0, 4294967294]
>>  drivers/gpu/drm/tegra/hub.c:1106:17: note: ‘snprintf’ output between 6 and 15 bytes into a destination of size 8
>
> I wish there was (perhaps there is?) a better way to annotate that i
> will always be within a given range. In practice this is always going to
> be smaller than 10 and even in future hardware I wouldn't expect this to
> ever exceed anything like 32 or 64, so 8 characters is already generous.

I assume you could do

	snprintf(id, sizeof(id), "wgrp%u", (unsigned char)i);

but it's perhaps less obvious than just increasing the size of the
buffer.

BR,
Jani.

>
> Thierry
>
>> 
>> Signed-off-by: Lee Jones <lee@kernel.org>
>> ---
>> Cc: Thierry Reding <thierry.reding@gmail.com>
>> Cc: Mikko Perttunen <mperttunen@nvidia.com>
>> Cc: David Airlie <airlied@gmail.com>
>> Cc: Daniel Vetter <daniel@ffwll.ch>
>> Cc: Jonathan Hunter <jonathanh@nvidia.com>
>> Cc: Philipp Zabel <p.zabel@pengutronix.de>
>> Cc: dri-devel@lists.freedesktop.org
>> Cc: linux-tegra@vger.kernel.org
>> ---
>>  drivers/gpu/drm/tegra/hub.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/drivers/gpu/drm/tegra/hub.c b/drivers/gpu/drm/tegra/hub.c
>> index 1af5f8318d914..f21e57e8599ee 100644
>> --- a/drivers/gpu/drm/tegra/hub.c
>> +++ b/drivers/gpu/drm/tegra/hub.c
>> @@ -1101,7 +1101,7 @@ static int tegra_display_hub_probe(struct platform_device *pdev)
>>  
>>  	for (i = 0; i < hub->soc->num_wgrps; i++) {
>>  		struct tegra_windowgroup *wgrp = &hub->wgrps[i];
>> -		char id[8];
>> +		char id[16];
>>  
>>  		snprintf(id, sizeof(id), "wgrp%u", i);
>>  		mutex_init(&wgrp->lock);
>> -- 
>> 2.42.0.rc1.204.g551eb34607-goog
>> 

-- 
Jani Nikula, Intel Open Source Graphics Center

Re: [PATCH 15/20] drm/tegra/hub: Increase buffer size to ensure all possible values can be stored

[Lee Jones]

On Thu, 24 Aug 2023, Jani Nikula wrote:

> On Thu, 24 Aug 2023, Thierry Reding <thierry.reding@gmail.com> wrote:
> > On Thu, Aug 24, 2023 at 08:37:00AM +0100, Lee Jones wrote:
> >> When converting from int to string, we must allow for up to 10-chars (2147483647).
> >> 
> >> Fixes the following W=1 kernel build warning(s):
> >> 
> >>  drivers/gpu/drm/tegra/hub.c: In function ‘tegra_display_hub_probe’:
> >>  drivers/gpu/drm/tegra/hub.c:1106:47: warning: ‘%u’ directive output may be truncated writing between 1 and 10 bytes into a region of size 4 [-Wformat-truncation=]
> >>  drivers/gpu/drm/tegra/hub.c:1106:42: note: directive argument in the range [0, 4294967294]
> >>  drivers/gpu/drm/tegra/hub.c:1106:17: note: ‘snprintf’ output between 6 and 15 bytes into a destination of size 8
> >
> > I wish there was (perhaps there is?) a better way to annotate that i
> > will always be within a given range. In practice this is always going to
> > be smaller than 10 and even in future hardware I wouldn't expect this to
> > ever exceed anything like 32 or 64, so 8 characters is already generous.
> 
> I assume you could do
> 
> 	snprintf(id, sizeof(id), "wgrp%u", (unsigned char)i);
> 
> but it's perhaps less obvious than just increasing the size of the
> buffer.

I had the very same thought process.

-- 
Lee Jones [李琼斯]

Re: [PATCH (set 1) 00/20] Rid W=1 warnings from GPU

[Lee Jones]

On Thu, 24 Aug 2023, Jani Nikula wrote:

> On Thu, 24 Aug 2023, Lee Jones <lee@kernel.org> wrote:
> > This set is part of a larger effort attempting to clean-up W=1
> > kernel builds, which are currently overwhelmingly riddled with
> > niggly little warnings.
> 
> The next question is, how do we keep it W=1 clean going forward?

My plan was to fix them all, then move each warning to W=0.

Arnd recently submitted a set doing just that for a bunch of them.

https://lore.kernel.org/all/20230811140327.3754597-1-arnd@kernel.org/

I like to think a bunch of this is built on top of my previous efforts.

GPU is a particularly tricky though - the warnings seem to come in faster
than I can squash them.  Maybe the maintainers can find a way to test
new patches on merge?

> Most people don't use W=1 because it's too noisy, so it's a bit of a
> catch-22.
> 
> In i915, we enable a lot of W=1 warnings using subdir-ccflags-y in our
> Makefile. For CI/developer use we also enable kernel-doc warnings by
> default.
> 
> Should we start enabling some of those warning flags in drm/Makefile to
> to keep the entire subsystem warning free?

That would we awesome!  We'd just need buy-in.

-- 
Lee Jones [李琼斯]

Re: [PATCH (set 1) 00/20] Rid W=1 warnings from GPU

[Lee Jones]

On Thu, 24 Aug 2023, Lee Jones wrote:

> On Thu, 24 Aug 2023, Jani Nikula wrote:
> 
> > On Thu, 24 Aug 2023, Lee Jones <lee@kernel.org> wrote:
> > > This set is part of a larger effort attempting to clean-up W=1
> > > kernel builds, which are currently overwhelmingly riddled with
> > > niggly little warnings.
> > 
> > The next question is, how do we keep it W=1 clean going forward?
> 
> My plan was to fix them all, then move each warning to W=0.

Some history:

- Starting with v5.8-rc1:       18867
- 2020-07-01:                   18089
- 2020-07-07:                   17288
- 2020-07-17:                   15762
- 2020-07-20:                   15724
- 2020-07-23:                   15116
- 2020-08-12:                   15184
- 2020-10-19:                   10909
- 2020-11-04:                    9385
- 2021-01-04:                    5478
- 2021-01-12                     4749
- 2021-01-29                     4911
- 2021-04-07                     3594
- 2021-05-20                     2938
- 2021-07-01                     2587
- 2023-02-10                     2587
- 2023-08-22                     1650

> Arnd recently submitted a set doing just that for a bunch of them.
> 
> https://lore.kernel.org/all/20230811140327.3754597-1-arnd@kernel.org/
> 
> I like to think a bunch of this is built on top of my previous efforts.
> 
> GPU is a particularly tricky though - the warnings seem to come in faster
> than I can squash them.  Maybe the maintainers can find a way to test
> new patches on merge?
> 
> > Most people don't use W=1 because it's too noisy, so it's a bit of a
> > catch-22.
> > 
> > In i915, we enable a lot of W=1 warnings using subdir-ccflags-y in our
> > Makefile. For CI/developer use we also enable kernel-doc warnings by
> > default.
> > 
> > Should we start enabling some of those warning flags in drm/Makefile to
> > to keep the entire subsystem warning free?
> 
> That would we awesome!  We'd just need buy-in.

-- 
Lee Jones [李琼斯]

Re: [PATCH (set 1) 00/20] Rid W=1 warnings from GPU

[Lee Jones]

On Thu, 24 Aug 2023, Maxime Ripard wrote:

> Hi,
> 
> On Thu, Aug 24, 2023 at 10:59:54AM +0200, Maxime Ripard wrote:
> > On Thu, 24 Aug 2023 08:36:45 +0100, Lee Jones wrote:
> > > This set is part of a larger effort attempting to clean-up W=1
> > > kernel builds, which are currently overwhelmingly riddled with
> > > niggly little warnings.
> > > 
> > > Cc: Alex Deucher <alexander.deucher@amd.com>
> > > Cc: amd-gfx@lists.freedesktop.org
> > > Cc: Ben Skeggs <bskeggs@redhat.com>
> > > Cc: "Christian König" <christian.koenig@amd.com>
> > > Cc: Daniel Vetter <daniel@ffwll.ch>
> > > Cc: Danilo Krummrich <dakr@redhat.com>
> > > Cc: David Airlie <airlied@gmail.com>
> > > Cc: dri-devel@lists.freedesktop.org
> > > Cc: Fabio Estevam <festevam@gmail.com>
> > > Cc: Gourav Samaiya <gsamaiya@nvidia.com>
> > > Cc: Hawking Zhang <Hawking.Zhang@amd.com>
> > > Cc: Hyun Kwon <hyun.kwon@xilinx.com>
> > > Cc: Jerome Glisse <glisse@freedesktop.org>
> > > Cc: Jonathan Hunter <jonathanh@nvidia.com>
> > > Cc: Karol Herbst <kherbst@redhat.com>
> > > Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > Cc: linaro-mm-sig@lists.linaro.org
> > > Cc: linux-arm-kernel@lists.infradead.org
> > > Cc: linux-media@vger.kernel.org
> > > Cc: linux-tegra@vger.kernel.org
> > > Cc: Luben Tuikov <luben.tuikov@amd.com>
> > > Cc: Lyude Paul <lyude@redhat.com>
> > > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> > > Cc: "Maíra Canal" <mairacanal@riseup.net>
> > > Cc: Mario Limonciello <mario.limonciello@amd.com>
> > > Cc: Maxime Ripard <mripard@kernel.org>
> > > Cc: Michal Simek <michal.simek@xilinx.com>
> > > Cc: Mikko Perttunen <mperttunen@nvidia.com>
> > > Cc: nouveau@lists.freedesktop.org
> > > Cc: NXP Linux Team <linux-imx@nxp.com>
> > > Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
> > > Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
> > > Cc: Philipp Zabel <p.zabel@pengutronix.de>
> > > Cc: Sascha Hauer <s.hauer@pengutronix.de>
> > > Cc: Shashank Sharma <shashank.sharma@amd.com>
> > > Cc: Shawn Guo <shawnguo@kernel.org>
> > > Cc: Stanley Yang <Stanley.Yang@amd.com>
> > > Cc: Sumit Semwal <sumit.semwal@linaro.org>
> > > Cc: Thierry Reding <thierry.reding@gmail.com>
> > > Cc: Thomas Zimmermann <tzimmermann@suse.de>
> > > 
> > > [...]
> > 
> > Applied to drm/drm-misc (drm-misc-fixes).
> 
> I got confused with b4 usage, but that wasn't actually applied. Only the
> three patches I explicitly mentioned were, sorry for the confusion.

:)

Thanks Maxime.

-- 
Lee Jones [李琼斯]

Re: [PATCH (set 1) 00/20] Rid W=1 warnings from GPU

[Hamza Mahfooz]

On 8/24/23 08:07, Lee Jones wrote:
> On Thu, 24 Aug 2023, Jani Nikula wrote:
> 
>> On Thu, 24 Aug 2023, Lee Jones <lee@kernel.org> wrote:
>>> This set is part of a larger effort attempting to clean-up W=1
>>> kernel builds, which are currently overwhelmingly riddled with
>>> niggly little warnings.
>>
>> The next question is, how do we keep it W=1 clean going forward?
> 
> My plan was to fix them all, then move each warning to W=0.
> 
> Arnd recently submitted a set doing just that for a bunch of them.
> 
> https://lore.kernel.org/all/20230811140327.3754597-1-arnd@kernel.org/
> 
> I like to think a bunch of this is built on top of my previous efforts.
> 
> GPU is a particularly tricky though - the warnings seem to come in faster
> than I can squash them.  Maybe the maintainers can find a way to test
> new patches on merge?

I guess on that note, do you know if there is a way to run
`scripts/kernel-doc` on patches instead of whole files? That would make
much easier to block new kernel-doc issues from appearing.

> 
>> Most people don't use W=1 because it's too noisy, so it's a bit of a
>> catch-22.
>>
>> In i915, we enable a lot of W=1 warnings using subdir-ccflags-y in our
>> Makefile. For CI/developer use we also enable kernel-doc warnings by
>> default.
>>
>> Should we start enabling some of those warning flags in drm/Makefile to
>> to keep the entire subsystem warning free?
> 
> That would we awesome!  We'd just need buy-in.
> 
-- 
Hamza

Re: [PATCH (set 1) 00/20] Rid W=1 warnings from GPU

[Lee Jones]

On Thu, 24 Aug 2023, Hamza Mahfooz wrote:

> 
> On 8/24/23 08:07, Lee Jones wrote:
> > On Thu, 24 Aug 2023, Jani Nikula wrote:
> > 
> > > On Thu, 24 Aug 2023, Lee Jones <lee@kernel.org> wrote:
> > > > This set is part of a larger effort attempting to clean-up W=1
> > > > kernel builds, which are currently overwhelmingly riddled with
> > > > niggly little warnings.
> > > 
> > > The next question is, how do we keep it W=1 clean going forward?
> > 
> > My plan was to fix them all, then move each warning to W=0.
> > 
> > Arnd recently submitted a set doing just that for a bunch of them.
> > 
> > https://lore.kernel.org/all/20230811140327.3754597-1-arnd@kernel.org/
> > 
> > I like to think a bunch of this is built on top of my previous efforts.
> > 
> > GPU is a particularly tricky though - the warnings seem to come in faster
> > than I can squash them.  Maybe the maintainers can find a way to test
> > new patches on merge?
> 
> I guess on that note, do you know if there is a way to run
> `scripts/kernel-doc` on patches instead of whole files? That would make
> much easier to block new kernel-doc issues from appearing.

Not off hand.

When I run builds on patches I author, I run them twice concurrently.
Once on the commit I'm basing on and once on the HEAD of my patchset.  I
then diff the two.  So as long as the number of errors and warnings stay
the same or reduce, we're golden.

Perhaps the same method could be used with `kernel-doc`?

-- 
Lee Jones [李琼斯]

Re: [PATCH 15/20] drm/tegra/hub: Increase buffer size to ensure all possible values can be stored

[Thierry Reding]

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On Thu, Aug 24, 2023 at 01:01:24PM +0100, Lee Jones wrote:
> On Thu, 24 Aug 2023, Jani Nikula wrote:
> 
> > On Thu, 24 Aug 2023, Thierry Reding <thierry.reding@gmail.com> wrote:
> > > On Thu, Aug 24, 2023 at 08:37:00AM +0100, Lee Jones wrote:
> > >> When converting from int to string, we must allow for up to 10-chars (2147483647).
> > >> 
> > >> Fixes the following W=1 kernel build warning(s):
> > >> 
> > >>  drivers/gpu/drm/tegra/hub.c: In function ‘tegra_display_hub_probe’:
> > >>  drivers/gpu/drm/tegra/hub.c:1106:47: warning: ‘%u’ directive output may be truncated writing between 1 and 10 bytes into a region of size 4 [-Wformat-truncation=]
> > >>  drivers/gpu/drm/tegra/hub.c:1106:42: note: directive argument in the range [0, 4294967294]
> > >>  drivers/gpu/drm/tegra/hub.c:1106:17: note: ‘snprintf’ output between 6 and 15 bytes into a destination of size 8
> > >
> > > I wish there was (perhaps there is?) a better way to annotate that i
> > > will always be within a given range. In practice this is always going to
> > > be smaller than 10 and even in future hardware I wouldn't expect this to
> > > ever exceed anything like 32 or 64, so 8 characters is already generous.
> > 
> > I assume you could do
> > 
> > 	snprintf(id, sizeof(id), "wgrp%u", (unsigned char)i);
> > 
> > but it's perhaps less obvious than just increasing the size of the
> > buffer.
> 
> I had the very same thought process.

It's not a big deal, this happens all on the stack, so adding a couple
of bytes isn't going to hurt very much. Still with all the tooling that
we have it'd be nice if something could be added. Perhaps an alternative
would be to reject values for num_wgrp that are bigger than 32. With
that the compiler might have enough information not to warn about this.

Anyway, no need to spend any more time on this, I'm fine with the patch
as-is.

Thierry

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Re: [PATCH (set 1) 00/20] Rid W=1 warnings from GPU

[Michel Dänzer]

On 8/24/23 14:07, Lee Jones wrote:
> On Thu, 24 Aug 2023, Jani Nikula wrote:
>> On Thu, 24 Aug 2023, Lee Jones <lee@kernel.org> wrote:
>>> This set is part of a larger effort attempting to clean-up W=1
>>> kernel builds, which are currently overwhelmingly riddled with
>>> niggly little warnings.
>>
>> The next question is, how do we keep it W=1 clean going forward?
> 
> My plan was to fix them all, then move each warning to W=0.
> 
> Arnd recently submitted a set doing just that for a bunch of them.
> 
> https://lore.kernel.org/all/20230811140327.3754597-1-arnd@kernel.org/
> 
> I like to think a bunch of this is built on top of my previous efforts.
> 
> GPU is a particularly tricky though - the warnings seem to come in faster
> than I can squash them.  Maybe the maintainers can find a way to test
> new patches on merge?

One approach for this which has proved effective in Mesa and other projects is to make warnings fatal in CI which must pass for any changes to be merged. There is ongoing work toward introducing this for the DRM subsystem, using gitlab.freedesktop.org CI.


-- 
Earthling Michel Dänzer            |                  https://redhat.com
Libre software enthusiast          |         Mesa and Xwayland developer