[PATCH v3 2/3] drm/tegra: Request memory bandwidth for the display controller

Tomeu Vizoso
2014-08-19T08:39:38Z

For now the amount requested is based solely on the current mode's refresh
rate.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>

---

v3: * Fixed the bandwidth calculation, and have the units be mbps
---
drivers/gpu/drm/tegra/dc.c | 13 +++++++++++++
drivers/gpu/drm/tegra/drm.h | 3 +++
2 files changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
index 6553fd2..83a6d4b 100644
--- a/drivers/gpu/drm/tegra/dc.c
+++ b/drivers/gpu/drm/tegra/dc.c
@@ -9,6 +9,7 @@

#include <linux/clk.h>
#include <linux/debugfs.h>
+#include <linux/pm_qos.h>
#include <linux/reset.h>

#include "dc.h"
@@ -753,6 +754,8 @@ static void tegra_crtc_disable(struct drm_crtc *crtc)
}

drm_vblank_off(drm, dc->pipe);
+
+ pm_qos_update_request(&dc->qos_request, PM_QOS_DEFAULT_VALUE);
}

static bool tegra_crtc_mode_fixup(struct drm_crtc *crtc,
@@ -839,6 +842,7 @@ static int tegra_crtc_mode_set(struct drm_crtc *crtc,
struct tegra_dc *dc = to_tegra_dc(crtc);
struct tegra_dc_window window;
u32 value;
+ unsigned long bandwidth;
int err;

drm_vblank_pre_modeset(crtc->dev, dc->pipe);
@@ -879,6 +883,10 @@ static int tegra_crtc_mode_set(struct drm_crtc *crtc,
if (err < 0)
dev_err(dc->dev, "failed to enable root plane\n");

+ bandwidth = window.stride[0] * window.dst.h * 8;
+ bandwidth *= mode->clock * 1000 / 1024 / 1024;
+ pm_qos_update_request(&dc->qos_request, bandwidth);
+
return 0;
}

@@ -1499,6 +1507,9 @@ static int tegra_dc_probe(struct platform_device *pdev)
return err;
}

+ pm_qos_add_request(&dc->qos_request, PM_QOS_MEMORY_BANDWIDTH,
+ PM_QOS_DEFAULT_VALUE);
+
platform_set_drvdata(pdev, dc);

return 0;
@@ -1509,6 +1520,8 @@ static int tegra_dc_remove(struct platform_device *pdev)
struct tegra_dc *dc = platform_get_drvdata(pdev);
int err;

+ pm_qos_remove_request(&dc->qos_request);
+
err = host1x_client_unregister(&dc->client);
if (err < 0) {
dev_err(&pdev->dev, "failed to unregister host1x client: %d\n",
diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h
index e89c70f..a99e533d 100644
--- a/drivers/gpu/drm/tegra/drm.h
+++ b/drivers/gpu/drm/tegra/drm.h
@@ -12,6 +12,7 @@

#include <uapi/drm/tegra_drm.h>
#include <linux/host1x.h>
+#include <linux/pm_qos.h>

#include <drm/drmP.h>
#include <drm/drm_crtc_helper.h>
@@ -120,6 +121,8 @@ struct tegra_dc {
struct drm_pending_vblank_event *event;

const struct tegra_dc_soc_info *soc;
+
+ struct pm_qos_request qos_request;
};

static inline struct tegra_dc *
--
1.9.3