| Message ID | 20201201103757.32165-1-martin.kepplinger@puri.sm (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm: mxsfb: Add interconnect path request | expand |
Am Dienstag, den 01.12.2020, 11:37 +0100 schrieb Martin Kepplinger: > Add interconnect support to mxsfb so that it is able to request enough > bandwidth to DDR for display output to work. > > Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm> > --- > drivers/gpu/drm/mxsfb/mxsfb_drv.c | 33 +++++++++++++++++++++++++++++++ > drivers/gpu/drm/mxsfb/mxsfb_drv.h | 2 ++ > drivers/gpu/drm/mxsfb/mxsfb_kms.c | 13 ++++++++++++ > 3 files changed, 48 insertions(+) > > diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.c b/drivers/gpu/drm/mxsfb/mxsfb_drv.c > index 6faf17b6408d..b05e8e5f1e38 100644 > --- a/drivers/gpu/drm/mxsfb/mxsfb_drv.c > +++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.c > @@ -15,6 +15,7 @@ > #include <linux/of_device.h> > #include <linux/platform_device.h> > #include <linux/pm_runtime.h> > +#include <linux/interconnect.h> > > > > > #include <drm/drm_atomic_helper.h> > #include <drm/drm_bridge.h> > @@ -311,6 +312,34 @@ static const struct of_device_id mxsfb_dt_ids[] = { > }; > MODULE_DEVICE_TABLE(of, mxsfb_dt_ids); > > + > +static int mxsfb_init_icc(struct platform_device *pdev) > +{ > + struct drm_device *drm = platform_get_drvdata(pdev); > + struct mxsfb_drm_private *mxsfb = drm->dev_private; > + int ret; > + > + /* Optional interconnect request */ > + mxsfb->icc_path = devm_of_icc_get(&pdev->dev, "lcdif-dram"); > + if (IS_ERR(mxsfb->icc_path)) { > + ret = PTR_ERR(mxsfb->icc_path); > + if (ret == -EPROBE_DEFER) > + return ret; > + > + mxsfb->icc_path = NULL; > + dev_dbg(drm->dev, > + "No interconnect may cause display underflows!\n"); > + } > + > + ret = icc_set_bw(mxsfb->icc_path, 0, MBps_to_icc(700)); Shouldn't this be proportional to the current mode, instead of a fixed value? 700MB looks like 1080p@60Hz@32bpp with a bit of headroom, but there are many valid use-cases where significantly smaller displays are connected to the eLCDIF. Also it doesn't cover the case where an overlay is active, which needs additional bandwidth. > + if (ret) { > + dev_err(drm->dev, "%s: icc_set_bw failed: %d\n", __func__, ret); > + return ret; > + } > + > + return 0; > +} > + [...] > #include <drm/drm_atomic.h> > #include <drm/drm_atomic_helper.h> > @@ -310,6 +311,12 @@ static void mxsfb_crtc_atomic_enable(struct drm_crtc *crtc, > struct mxsfb_drm_private *mxsfb = to_mxsfb_drm_private(crtc->dev); > struct drm_device *drm = mxsfb->drm; > dma_addr_t paddr; > + int ret; > + > + ret = icc_enable(mxsfb->icc_path); > + if (ret) > + dev_err_ratelimited(drm->dev, "%s: icc_enable failed: %d\n", > + __func__, ret); Why ratelimited? I wouldn't expect atomic enable/disable to be called often enough for this to make any difference. Regards, Lucas > > pm_runtime_get_sync(drm->dev); > mxsfb_enable_axi_clk(mxsfb);
diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.c b/drivers/gpu/drm/mxsfb/mxsfb_drv.c index 6faf17b6408d..b05e8e5f1e38 100644 --- a/drivers/gpu/drm/mxsfb/mxsfb_drv.c +++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.c @@ -15,6 +15,7 @@ #include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> +#include <linux/interconnect.h> #include <drm/drm_atomic_helper.h> #include <drm/drm_bridge.h> @@ -311,6 +312,34 @@ static const struct of_device_id mxsfb_dt_ids[] = { }; MODULE_DEVICE_TABLE(of, mxsfb_dt_ids); + +static int mxsfb_init_icc(struct platform_device *pdev) +{ + struct drm_device *drm = platform_get_drvdata(pdev); + struct mxsfb_drm_private *mxsfb = drm->dev_private; + int ret; + + /* Optional interconnect request */ + mxsfb->icc_path = devm_of_icc_get(&pdev->dev, "lcdif-dram"); + if (IS_ERR(mxsfb->icc_path)) { + ret = PTR_ERR(mxsfb->icc_path); + if (ret == -EPROBE_DEFER) + return ret; + + mxsfb->icc_path = NULL; + dev_dbg(drm->dev, + "No interconnect may cause display underflows!\n"); + } + + ret = icc_set_bw(mxsfb->icc_path, 0, MBps_to_icc(700)); + if (ret) { + dev_err(drm->dev, "%s: icc_set_bw failed: %d\n", __func__, ret); + return ret; + } + + return 0; +} + static int mxsfb_probe(struct platform_device *pdev) { struct drm_device *drm; @@ -329,6 +358,10 @@ static int mxsfb_probe(struct platform_device *pdev) if (ret) goto err_free; + ret = mxsfb_init_icc(pdev); + if (ret) + goto err_free; + ret = drm_dev_register(drm, 0); if (ret) goto err_unload; diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.h b/drivers/gpu/drm/mxsfb/mxsfb_drv.h index 399d23e91ed1..d74ff4818e62 100644 --- a/drivers/gpu/drm/mxsfb/mxsfb_drv.h +++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.h @@ -41,6 +41,8 @@ struct mxsfb_drm_private { struct drm_encoder encoder; struct drm_connector *connector; struct drm_bridge *bridge; + + struct icc_path *icc_path; }; static inline struct mxsfb_drm_private * diff --git a/drivers/gpu/drm/mxsfb/mxsfb_kms.c b/drivers/gpu/drm/mxsfb/mxsfb_kms.c index 3e1bb0aefb87..8925ee7deeaa 100644 --- a/drivers/gpu/drm/mxsfb/mxsfb_kms.c +++ b/drivers/gpu/drm/mxsfb/mxsfb_kms.c @@ -13,6 +13,7 @@ #include <linux/iopoll.h> #include <linux/pm_runtime.h> #include <linux/spinlock.h> +#include <linux/interconnect.h> #include <drm/drm_atomic.h> #include <drm/drm_atomic_helper.h> @@ -310,6 +311,12 @@ static void mxsfb_crtc_atomic_enable(struct drm_crtc *crtc, struct mxsfb_drm_private *mxsfb = to_mxsfb_drm_private(crtc->dev); struct drm_device *drm = mxsfb->drm; dma_addr_t paddr; + int ret; + + ret = icc_enable(mxsfb->icc_path); + if (ret) + dev_err_ratelimited(drm->dev, "%s: icc_enable failed: %d\n", + __func__, ret); pm_runtime_get_sync(drm->dev); mxsfb_enable_axi_clk(mxsfb); @@ -334,6 +341,7 @@ static void mxsfb_crtc_atomic_disable(struct drm_crtc *crtc, struct mxsfb_drm_private *mxsfb = to_mxsfb_drm_private(crtc->dev); struct drm_device *drm = mxsfb->drm; struct drm_pending_vblank_event *event; + int ret; mxsfb_disable_controller(mxsfb); @@ -349,6 +357,11 @@ static void mxsfb_crtc_atomic_disable(struct drm_crtc *crtc, mxsfb_disable_axi_clk(mxsfb); pm_runtime_put_sync(drm->dev); + + ret = icc_disable(mxsfb->icc_path); + if (ret) + dev_err_ratelimited(drm->dev, "%s: icc_disable failed: %d\n", + __func__, ret); } static int mxsfb_crtc_enable_vblank(struct drm_crtc *crtc)
Add interconnect support to mxsfb so that it is able to request enough bandwidth to DDR for display output to work. Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm> --- drivers/gpu/drm/mxsfb/mxsfb_drv.c | 33 +++++++++++++++++++++++++++++++ drivers/gpu/drm/mxsfb/mxsfb_drv.h | 2 ++ drivers/gpu/drm/mxsfb/mxsfb_kms.c | 13 ++++++++++++ 3 files changed, 48 insertions(+)