On Fri, May 24, 2013 at 07:05:12PM -0300, Paulo Zanoni wrote:
> From: Paulo Zanoni <paulo.r.zanoni at intel.com>
>
> We were previously only setting the WM_PIPE registers, now we are
> setting the LP watermark registers. This should allow deeper PC
> states, resulting in power savings.
>
> We're only using 1/2 data buffer partitioning for now.
>
> v2: Merge both hsw_compute_pri_wm_* functions (Ville)
>
> Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
> ---
> drivers/gpu/drm/i915/i915_reg.h | 4 +
> drivers/gpu/drm/i915/intel_pm.c | 201 ++++++++++++++++++++++++++++++++++++----
> 2 files changed, 187 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index e86606c..58230ea 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -3057,6 +3057,10 @@
> #define WM3S_LP_IVB 0x45128
> #define WM1S_LP_EN (1<<31)
>
> +#define HSW_WM_LP_VAL(lat, fbc, pri, cur) \
> + (WM3_LP_EN | ((lat) << WM1_LP_LATENCY_SHIFT) | \
> + ((fbc) << WM1_LP_FBC_SHIFT) | ((pri) << WM1_LP_SR_SHIFT) | (cur))
> +
> /* Memory latency timer register */
> #define MLTR_ILK 0x11222
> #define MLTR_WM1_SHIFT 0
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index ef58a1a..872e2a8 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -2129,6 +2129,12 @@ static uint32_t hsw_wm_method2(uint32_t pixel_rate, uint32_t pipe_htotal,
> return ret;
> }
>
> +static uint32_t hsw_wm_fbc(uint32_t pri_val, uint32_t horiz_pixels,
> + uint8_t bytes_per_pixel)
> +{
> + return DIV_ROUND_UP(pri_val * 64, horiz_pixels * bytes_per_pixel) + 2;
> +}
> +
> struct hsw_pipe_wm_parameters {
> bool active;
> bool sprite_enabled;
> @@ -2142,11 +2148,28 @@ struct hsw_pipe_wm_parameters {
> uint32_t pixel_rate;
> };
>
> +struct hsw_wm_maximums {
> + uint16_t pri;
> + uint16_t spr;
> + uint16_t cur;
> + uint16_t fbc;
> +};
> +
> +struct hsw_lp_wm_result {
> + bool enable;
> + bool fbc_enable;
> + uint32_t pri_val;
> + uint32_t spr_val;
> + uint32_t cur_val;
> + uint32_t fbc_val;
> +};
> +
> struct hsw_wm_values {
> uint32_t wm_pipe[3];
> uint32_t wm_lp[3];
> uint32_t wm_lp_spr[3];
> uint32_t wm_linetime[3];
> + bool enable_fbc_wm;
> };
>
> enum hsw_data_buf_partitioning {
> @@ -2154,17 +2177,31 @@ enum hsw_data_buf_partitioning {
> HSW_DATA_BUF_PART_5_6,
> };
>
> -/* Only for WM_PIPE. */
> -static uint32_t hsw_compute_pri_wm_pipe(struct hsw_pipe_wm_parameters *params,
> - uint32_t mem_value)
> +/* For both WM_PIPE and WM_LP. */
> +static uint32_t hsw_compute_pri_wm(struct hsw_pipe_wm_parameters *params,
> + uint32_t mem_value,
> + bool is_lp)
> {
> + uint32_t method1, method2;
> +
> /* TODO: for now, assume the primary plane is always enabled. */
> if (!params->active)
> return 0;
>
> - return hsw_wm_method1(params->pixel_rate,
> - params->pri_bytes_per_pixel,
> - mem_value);
> + method1 = hsw_wm_method1(params->pixel_rate,
> + params->pri_bytes_per_pixel,
> + mem_value);
> +
> + if (!is_lp)
> + return method1;
> +
> + method2 = hsw_wm_method2(params->pixel_rate,
> + params->pipe_htotal,
> + params->pri_horiz_pixels,
> + params->pri_bytes_per_pixel,
> + mem_value);
> +
> + return min(method1, method2);
> }
>
> /* For both WM_PIPE and WM_LP. */
> @@ -2201,13 +2238,59 @@ static uint32_t hsw_compute_cur_wm(struct hsw_pipe_wm_parameters *params,
> mem_value);
> }
>
> +/* Only for WM_LP. */
> +static uint32_t hsw_compute_fbc_wm(struct hsw_pipe_wm_parameters *params,
> + uint32_t pri_val,
> + uint32_t mem_value)
> +{
> + if (!params->active)
> + return 0;
> +
> + return hsw_wm_fbc(pri_val,
> + params->pri_horiz_pixels,
> + params->pri_bytes_per_pixel);
> +}
> +
> +static void hsw_compute_lp_wm(uint32_t mem_value, struct hsw_wm_maximums *max,
> + struct hsw_pipe_wm_parameters *params,
> + struct hsw_lp_wm_result *result)
> +{
> + enum pipe pipe;
> + uint32_t pri_val[3], spr_val[3], cur_val[3], fbc_val[3];
> +
> + for (pipe = PIPE_A; pipe <= PIPE_C; pipe++) {
> + struct hsw_pipe_wm_parameters *p = ¶ms[pipe];
> +
> + pri_val[pipe] = hsw_compute_pri_wm(p, mem_value, true);
> + spr_val[pipe] = hsw_compute_spr_wm(p, mem_value);
> + cur_val[pipe] = hsw_compute_cur_wm(p, mem_value);
> + fbc_val[pipe] = hsw_compute_fbc_wm(p, pri_val[pipe], mem_value);
> + }
> +
> + result->pri_val = max3(pri_val[0], pri_val[1], pri_val[2]);
> + result->spr_val = max3(spr_val[0], spr_val[1], spr_val[2]);
> + result->cur_val = max3(cur_val[0], cur_val[1], cur_val[2]);
> + result->fbc_val = max3(fbc_val[0], fbc_val[1], fbc_val[2]);
> +
> + if (result->fbc_val > max->fbc) {
> + result->fbc_enable = false;
> + result->fbc_val = 0;
> + } else {
> + result->fbc_enable = true;
> + }
> +
> + result->enable = result->pri_val <= max->pri &&
> + result->spr_val <= max->spr &&
> + result->cur_val <= max->cur;
> +}
> +
> static uint32_t hsw_compute_wm_pipe(struct drm_i915_private *dev_priv,
> uint32_t mem_value, enum pipe pipe,
> struct hsw_pipe_wm_parameters *params)
> {
> uint32_t pri_val, cur_val, spr_val;
>
> - pri_val = hsw_compute_pri_wm_pipe(params, mem_value);
> + pri_val = hsw_compute_pri_wm(params, mem_value, false);
> spr_val = hsw_compute_spr_wm(params, mem_value);
> cur_val = hsw_compute_cur_wm(params, mem_value);
>
> @@ -2250,13 +2333,15 @@ hsw_compute_linetime_wm(struct drm_device *dev, struct drm_crtc *crtc)
>
> static void hsw_compute_wm_parameters(struct drm_device *dev,
> struct hsw_pipe_wm_parameters *params,
> - uint32_t *wm)
> + uint32_t *wm,
> + struct hsw_wm_maximums *lp_max_1_2)
> {
> struct drm_i915_private *dev_priv = dev->dev_private;
> struct drm_crtc *crtc;
> struct drm_plane *plane;
> uint64_t sskpd = I915_READ64(MCH_SSKPD);
> enum pipe pipe;
> + int pipes_active = 0, sprites_enabled = 0;
>
> if ((sskpd >> 56) & 0xFF)
> wm[0] = (sskpd >> 56) & 0xFF;
> @@ -2278,6 +2363,8 @@ static void hsw_compute_wm_parameters(struct drm_device *dev,
> if (!p->active)
> continue;
>
> + pipes_active++;
> +
> p->pipe_htotal = intel_crtc->config.adjusted_mode.htotal;
> p->pixel_rate = hsw_wm_get_pixel_rate(dev, crtc);
> p->pri_bytes_per_pixel = crtc->fb->bits_per_pixel / 8;
> @@ -2297,25 +2384,89 @@ static void hsw_compute_wm_parameters(struct drm_device *dev,
> p->sprite_enabled = intel_plane->wm.enable;
> p->spr_bytes_per_pixel = intel_plane->wm.bytes_per_pixel;
> p->spr_horiz_pixels = intel_plane->wm.horiz_pixels;
> +
> + if (p->sprite_enabled)
> + sprites_enabled++;
> + }
> +
> + if (pipes_active > 1) {
> + lp_max_1_2->pri = sprites_enabled ? 128 : 256;
> + lp_max_1_2->spr = 128;
> + lp_max_1_2->cur = 64;
> + } else {
> + lp_max_1_2->pri = sprites_enabled ? 384 : 768;
> + lp_max_1_2->spr = 384;
> + lp_max_1_2->cur = 255;
> }
> + lp_max_1_2->fbc = 15;
> }
>
> static void hsw_compute_wm_results(struct drm_device *dev,
> struct hsw_pipe_wm_parameters *params,
> uint32_t *wm,
> + struct hsw_wm_maximums *lp_maximums,
> struct hsw_wm_values *results)
> {
> struct drm_i915_private *dev_priv = dev->dev_private;
> struct drm_crtc *crtc;
> + struct hsw_lp_wm_result lp_results[4];
> enum pipe pipe;
> + int i;
>
> - /* No support for LP WMs yet. */
> - results->wm_lp[2] = 0;
> - results->wm_lp[1] = 0;
> - results->wm_lp[0] = 0;
> - results->wm_lp_spr[2] = 0;
> - results->wm_lp_spr[1] = 0;
> - results->wm_lp_spr[0] = 0;
> + hsw_compute_lp_wm(wm[1], lp_maximums, params, &lp_results[0]);
> + hsw_compute_lp_wm(wm[2], lp_maximums, params, &lp_results[1]);
> + hsw_compute_lp_wm(wm[3], lp_maximums, params, &lp_results[2]);
> + hsw_compute_lp_wm(wm[4], lp_maximums, params, &lp_results[3]);
> +
> + /* The spec says it is preferred to disable FBC WMs instead of disabling
> + * a WM level. */
> + results->enable_fbc_wm = true;
> + for (i = 0; i < 4; i++) {
> + if (lp_results[i].enable && !lp_results[i].fbc_enable) {
> + results->enable_fbc_wm = false;
> + break;
> + }
> + }
> +
> + if (lp_results[3].enable) {
Here you seem to assume that if lp[3] is valid, that also lp[2] and lp[0]
are valid...
> + results->wm_lp[2] = HSW_WM_LP_VAL(8, lp_results[3].fbc_val,
> + lp_results[3].pri_val,
> + lp_results[3].cur_val);
> + results->wm_lp_spr[2] = lp_results[3].spr_val;
> + } else if (lp_results[2].enable) {
> + results->wm_lp[2] = HSW_WM_LP_VAL(6, lp_results[2].fbc_val,
> + lp_results[2].pri_val,
> + lp_results[2].cur_val);
> + results->wm_lp_spr[2] = lp_results[2].spr_val;
> + } else {
> + results->wm_lp[2] = 0;
> + results->wm_lp_spr[2] = 0;
> + }
> +
> + if (lp_results[3].enable && lp_results[2].enable) {
... but here you check if lp[2] is actually valid.
So it seems that in theory (if the latency values are really weird) the code
could enable LP3 and leave LP2 or LP1 disabled, which is illegal.
I think this could be cleared up a bit like so:
struct hsw_lp_wm_result lp_results[4] = {};
for (level = 1; level <= 4; level++)
if (!hsw_compute_lp_wm(wm[level], lp_maximums, params, &lp_results[level-1]))
break;
and obviously have hsw_compute_lp_wm() return result->enable. It could
also save a few cycles by not computing watermark levels that will never
be used.
To simplify the results handling you could take another page out of my
WM patch. Something like this:
memset(results, 0, sizeof *results);
for (wm_lp = 1; wm_lp <= 3; wm_lp++) {
int level = wm_lp + (wm_lp >= 2 && lp_results[3].enable)
const struct hsw_lp_wm_result *r = &lp_results[level-1];
if (!r->enable)
break;
results->wm_lp[wm_lp] = HSW_WM_LP_VAL(level << 1, r->fbc_val, r->pri_val, r->cur_val);
results->wm_lp_spr[wm_lp] = r->spr_val;
}
Quite a bit less code, and avoids all those awkward checks for which
levels are valid.
> + results->wm_lp[1] = HSW_WM_LP_VAL(6, lp_results[2].fbc_val,
> + lp_results[2].pri_val,
> + lp_results[2].cur_val);
> + results->wm_lp_spr[1] = lp_results[2].spr_val;
> + } else if (!lp_results[3].enable && lp_results[1].enable) {
> + results->wm_lp[1] = HSW_WM_LP_VAL(4, lp_results[1].fbc_val,
> + lp_results[1].pri_val,
> + lp_results[1].cur_val);
> + results->wm_lp_spr[1] = lp_results[1].spr_val;
> + } else {
> + results->wm_lp[1] = 0;
> + results->wm_lp_spr[1] = 0;
> + }
> +
> + if (lp_results[0].enable) {
> + results->wm_lp[0] = HSW_WM_LP_VAL(2, lp_results[0].fbc_val,
> + lp_results[0].pri_val,
> + lp_results[0].cur_val);
> + results->wm_lp_spr[0] = lp_results[0].spr_val;
> + } else {
> + results->wm_lp[0] = 0;
> + results->wm_lp_spr[0] = 0;
> + }
>
> for_each_pipe(pipe)
> results->wm_pipe[pipe] = hsw_compute_wm_pipe(dev_priv, wm[0],
> @@ -2339,6 +2490,7 @@ static void hsw_write_wm_values(struct drm_i915_private *dev_priv,
> struct hsw_wm_values previous;
> uint32_t val;
> enum hsw_data_buf_partitioning prev_partitioning;
> + bool prev_enable_fbc_wm;
>
> previous.wm_pipe[0] = I915_READ(WM0_PIPEA_ILK);
> previous.wm_pipe[1] = I915_READ(WM0_PIPEB_ILK);
> @@ -2356,11 +2508,14 @@ static void hsw_write_wm_values(struct drm_i915_private *dev_priv,
> prev_partitioning = (I915_READ(WM_MISC) & WM_MISC_DATA_PARTITION_5_6) ?
> HSW_DATA_BUF_PART_5_6 : HSW_DATA_BUF_PART_1_2;
>
> + prev_enable_fbc_wm = !(I915_READ(DISP_ARB_CTL) & DISP_FBC_WM_DIS);
> +
> if (memcmp(results->wm_pipe, previous.wm_pipe, 3) == 0 &&
> memcmp(results->wm_lp, previous.wm_lp, 3) == 0 &&
> memcmp(results->wm_lp_spr, previous.wm_lp_spr, 3) == 0 &&
> memcmp(results->wm_linetime, previous.wm_linetime, 3) == 0 &&
> - partitioning == prev_partitioning)
> + partitioning == prev_partitioning &&
> + results->enable_fbc_wm == prev_enable_fbc_wm)
> return;
>
> if (previous.wm_lp[2] != 0)
> @@ -2393,6 +2548,15 @@ static void hsw_write_wm_values(struct drm_i915_private *dev_priv,
> I915_WRITE(WM_MISC, val);
> }
>
> + if (prev_enable_fbc_wm != results->enable_fbc_wm) {
> + val = I915_READ(DISP_ARB_CTL);
> + if (results->enable_fbc_wm)
> + val &= ~DISP_FBC_WM_DIS;
> + else
> + val |= DISP_FBC_WM_DIS;
> + I915_WRITE(DISP_ARB_CTL, val);
> + }
> +
> if (previous.wm_lp_spr[0] != results->wm_lp_spr[0])
> I915_WRITE(WM1S_LP_ILK, results->wm_lp_spr[0]);
> if (previous.wm_lp_spr[1] != results->wm_lp_spr[1])
> @@ -2411,12 +2575,13 @@ static void hsw_write_wm_values(struct drm_i915_private *dev_priv,
> static void haswell_update_wm(struct drm_device *dev)
> {
> struct drm_i915_private *dev_priv = dev->dev_private;
> + struct hsw_wm_maximums lp_max_1_2;
> struct hsw_pipe_wm_parameters params[3];
> struct hsw_wm_values results;
> uint32_t wm[5];
>
> - hsw_compute_wm_parameters(dev, params, wm);
> - hsw_compute_wm_results(dev, params, wm, &results);
> + hsw_compute_wm_parameters(dev, params, wm, &lp_max_1_2);
> + hsw_compute_wm_results(dev, params, wm, &lp_max_1_2, &results);
> hsw_write_wm_values(dev_priv, &results, HSW_DATA_BUF_PART_1_2);
> }
>
> --
> 1.8.1.2
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Ville Syrj?l?
Intel OTC
