Re: [PATCH 2/8] drm/ingenic: Simplify code by using hwdescs array

From: Thomas Zimmermann
Date: Sun Aug 08 2021 - 14:43:42 EST


Hi

Am 08.08.21 um 15:45 schrieb Paul Cercueil:
Instead of having one 'hwdesc' variable for the plane #0 and one for the
plane #1, use a 'hwdesc[2]' array, where the DMA hardware descriptors
are indexed by the plane's number.

Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 38 ++++++++++++-----------
1 file changed, 20 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
index e42eb43d8020..bc71ba44ccf4 100644
--- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
+++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
@@ -49,8 +49,7 @@ struct ingenic_dma_hwdesc {
} __aligned(16);
struct ingenic_dma_hwdescs {
- struct ingenic_dma_hwdesc hwdesc_f0;
- struct ingenic_dma_hwdesc hwdesc_f1;
+ struct ingenic_dma_hwdesc hwdesc[2];
struct ingenic_dma_hwdesc hwdesc_pal;
u16 palette[256] __aligned(16);
};
@@ -141,6 +140,13 @@ static inline struct ingenic_drm *drm_nb_get_priv(struct notifier_block *nb)
return container_of(nb, struct ingenic_drm, clock_nb);
}
+static inline dma_addr_t dma_hwdesc_addr(const struct ingenic_drm *priv, bool use_f1)

Using the plane index instead of a boolean would be more aligned to the way this function is being used.

+{
+ u32 offset = offsetof(struct ingenic_dma_hwdescs, hwdesc[use_f1]);

use_f1 is a function parameter. Is offsetof guaranteed to be evaluated at runtime?

+
+ return priv->dma_hwdescs_phys + offset;
+}
+
static int ingenic_drm_update_pixclk(struct notifier_block *nb,
unsigned long action,
void *data)
@@ -562,6 +568,7 @@ static void ingenic_drm_plane_atomic_update(struct drm_plane *plane,
struct ingenic_dma_hwdesc *hwdesc;
unsigned int width, height, cpp, offset;
dma_addr_t addr;
+ bool use_f1;
u32 fourcc;
if (newstate && newstate->fb) {
@@ -569,16 +576,14 @@ static void ingenic_drm_plane_atomic_update(struct drm_plane *plane,
drm_fb_cma_sync_non_coherent(&priv->drm, oldstate, newstate);
crtc_state = newstate->crtc->state;
+ use_f1 = priv->soc_info->has_osd && plane != &priv->f0;
addr = drm_fb_cma_get_gem_addr(newstate->fb, newstate, 0);
width = newstate->src_w >> 16;
height = newstate->src_h >> 16;
cpp = newstate->fb->format->cpp[0];
- if (!priv->soc_info->has_osd || plane == &priv->f0)
- hwdesc = &priv->dma_hwdescs->hwdesc_f0;
- else
- hwdesc = &priv->dma_hwdescs->hwdesc_f1;
+ hwdesc = &priv->dma_hwdescs->hwdesc[use_f1];

Maybe add a helper that looks up the hwdesc field for a given plane?

hwdesc->addr = addr;
hwdesc->cmd = JZ_LCD_CMD_EOF_IRQ | (width * height * cpp / 4);
@@ -591,9 +596,9 @@ static void ingenic_drm_plane_atomic_update(struct drm_plane *plane,
if (fourcc == DRM_FORMAT_C8)
offset = offsetof(struct ingenic_dma_hwdescs, hwdesc_pal);
else
- offset = offsetof(struct ingenic_dma_hwdescs, hwdesc_f0);
+ offset = offsetof(struct ingenic_dma_hwdescs, hwdesc[0]);
- priv->dma_hwdescs->hwdesc_f0.next = priv->dma_hwdescs_phys + offset;
+ priv->dma_hwdescs->hwdesc[0].next = priv->dma_hwdescs_phys + offset;

Maybe priv->dma_hwdescs_phys + offset could be computed in a more flexible helper than dma_hwdesc_addr().

crtc_state->color_mgmt_changed = fourcc == DRM_FORMAT_C8;
}
@@ -964,20 +969,17 @@ static int ingenic_drm_bind(struct device *dev, bool has_components)
/* Configure DMA hwdesc for foreground0 plane */
- dma_hwdesc_phys_f0 = priv->dma_hwdescs_phys
- + offsetof(struct ingenic_dma_hwdescs, hwdesc_f0);
- priv->dma_hwdescs->hwdesc_f0.next = dma_hwdesc_phys_f0;
- priv->dma_hwdescs->hwdesc_f0.id = 0xf0;
+ dma_hwdesc_phys_f0 = dma_hwdesc_addr(priv, 0);
+ priv->dma_hwdescs->hwdesc[0].next = dma_hwdesc_phys_f0;
+ priv->dma_hwdescs->hwdesc[0].id = 0xf0;
/* Configure DMA hwdesc for foreground1 plane */
- dma_hwdesc_phys_f1 = priv->dma_hwdescs_phys
- + offsetof(struct ingenic_dma_hwdescs, hwdesc_f1);
- priv->dma_hwdescs->hwdesc_f1.next = dma_hwdesc_phys_f1;
- priv->dma_hwdescs->hwdesc_f1.id = 0xf1;
+ dma_hwdesc_phys_f1 = dma_hwdesc_addr(priv, 1);
+ priv->dma_hwdescs->hwdesc[1].next = dma_hwdesc_phys_f1;
+ priv->dma_hwdescs->hwdesc[1].id = 0xf1;
/* Configure DMA hwdesc for palette */
- priv->dma_hwdescs->hwdesc_pal.next = priv->dma_hwdescs_phys
- + offsetof(struct ingenic_dma_hwdescs, hwdesc_f0);
+ priv->dma_hwdescs->hwdesc_pal.next = dma_hwdesc_phys_f0;
priv->dma_hwdescs->hwdesc_pal.id = 0xc0;
priv->dma_hwdescs->hwdesc_pal.addr = priv->dma_hwdescs_phys
+ offsetof(struct ingenic_dma_hwdescs, palette);


Could the setup in these three blocks be moved into a common helper?

Best regards
Thomas


--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer

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