[Intel-gfx] [PATCH] drm/i915: fix device info for devices without display

[Jani Nikula]

On Tue, 20 Sep 2022, Lucas De Marchi <lucas.demarchi at intel.com> wrote:
> On Mon, Sep 19, 2022 at 11:10:53AM +0300, Jani Nikula wrote:
>>On Fri, 16 Sep 2022, Lucas De Marchi <lucas.demarchi at intel.com> wrote:
>>> On Fri, Sep 16, 2022 at 11:26:42AM +0300, Jani Nikula wrote:
>>>>Commit 00c6cbfd4e8a ("drm/i915: move pipe_mask and cpu_transcoder_mask
>>>>to runtime info") moved the pipe_mask member from struct
>>>>intel_device_info to intel_runtime_info, but overlooked some of our
>>>>platforms initializing device info .display = {}. This is significant,
>>>>as pipe_mask is the single point of truth for a device having a display
>>>>or not; the platforms in question left pipe_mask to whatever was set for
>>>>the platforms they "inherit" from in the complex macro scheme we have.
>>>>
>>>>Add new NO_DISPLAY macro initializing .__runtime.pipe_mask = 0, which
>>>>will cause the device info .display sub-struct to be zeroed in
>>>>intel_device_info_runtime_init(). A better solution (or simply audit of
>>>>proper use of HAS_DISPLAY() checks) is required before moving forward
>>>>with [1].
>>>>
>>>>Also clear all the display related members in runtime info if there's no
>>>>display. The latter is a bit tedious, but it's for completeness at this
>>>>time, to ensure similar functionality as before.
>>>>
>>>>[1] https://lore.kernel.org/r/dfda1bf67f02ceb07c280b7a13216405fd1f7a34.1660137416.git.jani.nikula@intel.com
>>>>
>>>>Fixes: 00c6cbfd4e8a ("drm/i915: move pipe_mask and cpu_transcoder_mask to runtime info")
>>>>Cc: Lucas De Marchi <lucas.demarchi at intel.com>
>>>>Cc: Maarten Lankhort <maarten.lankhorst at linux.intel.com>
>>>>Signed-off-by: Jani Nikula <jani.nikula at intel.com>
>>>>---
>>>> drivers/gpu/drm/i915/i915_pci.c          | 11 ++++++-----
>>>> drivers/gpu/drm/i915/intel_device_info.c |  6 ++++++
>>>> 2 files changed, 12 insertions(+), 5 deletions(-)
>>>>
>>>>diff --git a/drivers/gpu/drm/i915/i915_pci.c b/drivers/gpu/drm/i915/i915_pci.c
>>>>index 77e7df21f539..cd4487a1d3be 100644
>>>>--- a/drivers/gpu/drm/i915/i915_pci.c
>>>>+++ b/drivers/gpu/drm/i915/i915_pci.c
>>>>@@ -41,6 +41,8 @@
>>>> 	.__runtime.media.ip.ver = (x), \
>>>> 	.__runtime.display.ip.ver = (x)
>>>>
>>>>+#define NO_DISPLAY .__runtime.pipe_mask = 0
>>>>+
>>>> #define I845_PIPE_OFFSETS \
>>>> 	.display.pipe_offsets = { \
>>>> 		[TRANSCODER_A] = PIPE_A_OFFSET,	\
>>>>@@ -519,9 +521,8 @@ static const struct intel_device_info ivb_m_gt2_info = {
>>>> static const struct intel_device_info ivb_q_info = {
>>>> 	GEN7_FEATURES,
>>>> 	PLATFORM(INTEL_IVYBRIDGE),
>>>>+	NO_DISPLAY,
>>>> 	.gt = 2,
>>>>-	.__runtime.pipe_mask = 0, /* legal, last one wins */
>>>>-	.__runtime.cpu_transcoder_mask = 0,
>>>> 	.has_l3_dpf = 1,
>>>> };
>>>>
>>>>@@ -1039,7 +1040,7 @@ static const struct intel_device_info xehpsdv_info = {
>>>> 	XE_HPM_FEATURES,
>>>> 	DGFX_FEATURES,
>>>> 	PLATFORM(INTEL_XEHPSDV),
>>>>-	.display = { },
>>>>+	NO_DISPLAY,
>>>> 	.has_64k_pages = 1,
>>>> 	.needs_compact_pt = 1,
>>>> 	.has_media_ratio_mode = 1,
>>>>@@ -1081,7 +1082,7 @@ static const struct intel_device_info dg2_info = {
>>>>
>>>> static const struct intel_device_info ats_m_info = {
>>>> 	DG2_FEATURES,
>>>>-	.display = { 0 },
>>>>+	NO_DISPLAY,
>>>> 	.require_force_probe = 1,
>>>> 	.tuning_thread_rr_after_dep = 1,
>>>> };
>>>>@@ -1103,7 +1104,7 @@ static const struct intel_device_info pvc_info = {
>>>> 	.__runtime.graphics.ip.rel = 60,
>>>> 	.__runtime.media.ip.rel = 60,
>>>> 	PLATFORM(INTEL_PONTEVECCHIO),
>>>>-	.display = { 0 },
>>>>+	NO_DISPLAY,
>>>> 	.has_flat_ccs = 0,
>>>> 	.__runtime.platform_engine_mask =
>>>> 		BIT(BCS0) |
>>>>diff --git a/drivers/gpu/drm/i915/intel_device_info.c b/drivers/gpu/drm/i915/intel_device_info.c
>>>>index 1434dc33cf49..20575eb77ea7 100644
>>>>--- a/drivers/gpu/drm/i915/intel_device_info.c
>>>>+++ b/drivers/gpu/drm/i915/intel_device_info.c
>>>>@@ -433,8 +433,14 @@ void intel_device_info_runtime_init(struct drm_i915_private *dev_priv)
>>>> 		dev_priv->drm.driver_features &= ~(DRIVER_MODESET |
>>>> 						   DRIVER_ATOMIC);
>>>> 		memset(&info->display, 0, sizeof(info->display));
>>>>+
>>>>+		runtime->cpu_transcoder_mask = 0;
>>>> 		memset(runtime->num_sprites, 0, sizeof(runtime->num_sprites));
>>>> 		memset(runtime->num_scalers, 0, sizeof(runtime->num_scalers));
>>>>+		runtime->fbc_mask = 0;
>>>>+		runtime->has_hdcp = false;
>>>>+		runtime->has_dmc = false;
>>>>+		runtime->has_dsc = false;
>>>
>>> why are these not inside __runtime.display?
>>
>>The short answer, because there isn't one. It's an anonymous struct for
>>now.
>
> /me confused... that doesn't really answer the question. Why would we
> not move these inside a display substruct? When moving stuff out of
> device_info.display.x, it seems the better place would be inside
> __runtime.display.x, not __runtime.x.
>
> I must be missing something here. We had a "recent" move of these flags
> lying around in device_info to be inside a display substruct -
> commit d53db442db36 ("drm/i915: Move display device info capabilities to its
> own struct") - to be able to keep the display flags together
> and zero them together.

So there were a few discussions spread around, but effectively the patch
has stalled here.

There's probably a bigger discussion to be had about the management of
mutable and immutable device info, and display and non-display info.

In the mean time, okay to merge this one?


BR,
Jani.


>
> Lucas De Marchi
>
>>
>>BR,
>>Jani.
>>
>>
>>-- 
>>Jani Nikula, Intel Open Source Graphics Center

-- 
Jani Nikula, Intel Open Source Graphics Center