drivers/gpu/drm/radeon/rv515.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/radeon/rv515.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/radeon/rv515.c
Extension
.c
Size
39934 bytes
Lines
1277
Domain
Driver Families
Bucket
drivers/gpu
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct rv515_watermark {
	u32        lb_request_fifo_depth;
	fixed20_12 num_line_pair;
	fixed20_12 estimated_width;
	fixed20_12 worst_case_latency;
	fixed20_12 consumption_rate;
	fixed20_12 active_time;
	fixed20_12 dbpp;
	fixed20_12 priority_mark_max;
	fixed20_12 priority_mark;
	fixed20_12 sclk;
};

static void rv515_crtc_bandwidth_compute(struct radeon_device *rdev,
					 struct radeon_crtc *crtc,
					 struct rv515_watermark *wm,
					 bool low)
{
	struct drm_display_mode *mode = &crtc->base.mode;
	fixed20_12 a, b, c;
	fixed20_12 pclk, request_fifo_depth, tolerable_latency, estimated_width;
	fixed20_12 consumption_time, line_time, chunk_time, read_delay_latency;
	fixed20_12 sclk;
	u32 selected_sclk;

	if (!crtc->base.enabled) {
		/* FIXME: wouldn't it better to set priority mark to maximum */
		wm->lb_request_fifo_depth = 4;
		return;
	}

	/* rv6xx, rv7xx */
	if ((rdev->family >= CHIP_RV610) &&
	    (rdev->pm.pm_method == PM_METHOD_DPM) && rdev->pm.dpm_enabled)
		selected_sclk = radeon_dpm_get_sclk(rdev, low);
	else
		selected_sclk = rdev->pm.current_sclk;

	/* sclk in Mhz */
	a.full = dfixed_const(100);
	sclk.full = dfixed_const(selected_sclk);
	sclk.full = dfixed_div(sclk, a);

	if (crtc->vsc.full > dfixed_const(2))
		wm->num_line_pair.full = dfixed_const(2);
	else
		wm->num_line_pair.full = dfixed_const(1);

	b.full = dfixed_const(mode->crtc_hdisplay);
	c.full = dfixed_const(256);
	a.full = dfixed_div(b, c);
	request_fifo_depth.full = dfixed_mul(a, wm->num_line_pair);
	request_fifo_depth.full = dfixed_ceil(request_fifo_depth);
	if (a.full < dfixed_const(4)) {
		wm->lb_request_fifo_depth = 4;
	} else {
		wm->lb_request_fifo_depth = dfixed_trunc(request_fifo_depth);
	}

	/* Determine consumption rate
	 *  pclk = pixel clock period(ns) = 1000 / (mode.clock / 1000)
	 *  vtaps = number of vertical taps,
	 *  vsc = vertical scaling ratio, defined as source/destination
	 *  hsc = horizontal scaling ration, defined as source/destination
	 */
	a.full = dfixed_const(mode->clock);
	b.full = dfixed_const(1000);
	a.full = dfixed_div(a, b);
	pclk.full = dfixed_div(b, a);
	if (crtc->rmx_type != RMX_OFF) {
		b.full = dfixed_const(2);
		if (crtc->vsc.full > b.full)
			b.full = crtc->vsc.full;
		b.full = dfixed_mul(b, crtc->hsc);
		c.full = dfixed_const(2);
		b.full = dfixed_div(b, c);
		consumption_time.full = dfixed_div(pclk, b);
	} else {
		consumption_time.full = pclk.full;
	}
	a.full = dfixed_const(1);
	wm->consumption_rate.full = dfixed_div(a, consumption_time);


	/* Determine line time
	 *  LineTime = total time for one line of displayhtotal
	 *  LineTime = total number of horizontal pixels
	 *  pclk = pixel clock period(ns)
	 */
	a.full = dfixed_const(crtc->base.mode.crtc_htotal);

Annotation

Implementation Notes