Re: [PATCH 1/2] drm: exynos: dsi: Convert to bridge driver

On 22.11.2021 08:06, Jagan Teki wrote:

Some display panels would come up with a non-DSI output, those can have an option to connect the DSI host by means of interface bridge converter.

This DSI to non-DSI interface bridge converter would requires DSI Host to handle drm bridge functionalities in order to DSI Host to Interface bridge.

This patch convert the existing to a drm bridge driver with a built-in encoder support for compatibility with existing component drivers.

Signed-off-by: Jagan Teki jagan@amarulasolutions.com

Note: Hi Marek Szyprowski,

Please test this on Panel and Bridge hardware.

I don't have good news, t crashes:

[drm] Exynos DRM: using 13800000.decon device for DMA mapping operations exynos-drm exynos-drm: bound 13800000.decon (ops decon_component_ops) exynos-drm exynos-drm: bound 13880000.decon (ops decon_component_ops) exynos-drm exynos-drm: bound 13930000.mic (ops exynos_mic_component_ops) [drm:drm_bridge_attach] *ERROR* failed to attach bridge /soc@0/dsi@13900000 to encoder TMDS-67: -22 exynos-drm exynos-drm: failed to bind 13900000.dsi (ops exynos_dsi_component_ops): -22 Internal error: synchronous external abort: 96000210 [#1] PREEMPT SMP Modules linked in: CPU: 2 PID: 74 Comm: kworker/u16:1 Not tainted 5.16.0-rc1+ #4141 Hardware name: Samsung TM2E board (DT) Workqueue: events_unbound deferred_probe_work_func pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : decon_atomic_disable+0x58/0xd4 lr : decon_atomic_disable+0x28/0xd4 sp : ffff80001390b940 x29: ffff80001390b940 x28: ffff80001259a000 x27: ffff000027f39e80 input: stmfts as /devices/platform/soc@0/14ed0000.hsi2c/i2c-3/3-0049/input/input0 x26: 00000000ffffffea x25: ffff000025a40280 x24: 0000000000000001 x23: ffff800011b55f98 x22: ffff0000315dc000 x21: ffff00002695d100 x20: ffff000027e7a080 x19: ffff0000315e6000 x18: 0000000000000000 x17: 645f736f6e797865 x16: 2073706f28206973 x15: 0000000000028ee0 x14: 0000000000000028 x13: 0000000000000001 x12: 0000000000000040 x11: ffff000023c18920 x10: ffff000023c18922 x9 : ffff8000126352f0 x8 : ffff000023c00270 x7 : 0000000000000000 x6 : ffff000023c00268 x5 : ffff000027e7a3a0 x4 : 0000000000000001 x3 : ffff000027e7a080 x2 : 0000000000000024 x1 : ffff800013bc8024 x0 : ffff0000246117c0 Call trace:  decon_atomic_disable+0x58/0xd4  decon_unbind+0x1c/0x3c  component_unbind+0x38/0x60  component_bind_all+0x16c/0x25c  exynos_drm_bind+0x104/0x1bc  try_to_bring_up_master+0x164/0x1d0  __component_add+0xa8/0x174  component_add+0x14/0x20  hdmi_probe+0x438/0x710  platform_probe+0x68/0xe0  really_probe.part.0+0x9c/0x31c  __driver_probe_device+0x98/0x144  driver_probe_device+0xc8/0x160  __device_attach_driver+0xb8/0x120  bus_for_each_drv+0x78/0xd0  __device_attach+0xd8/0x180  device_initial_probe+0x14/0x20  bus_probe_device+0x9c/0xa4  deferred_probe_work_func+0x88/0xc4  process_one_work+0x288/0x6f0  worker_thread+0x74/0x470  kthread+0x188/0x194  ret_from_fork+0x10/0x20 Code: 11002042 f9481c61 531e7442 8b020021 (88dffc21) ---[ end trace d73aff585b108954 ]--- Kernel panic - not syncing: synchronous external abort: Fatal exception SMP: stopping secondary CPUs Kernel Offset: disabled CPU features: 0x2,300071c2,00000846 Memory Limit: none ---[ end Kernel panic - not syncing: synchronous external abort: Fatal exception ]---

I will try to debug it a bit more once I find some spare time. I've applied only the first patch.

drivers/gpu/drm/exynos/exynos_drm_dsi.c | 73 +++++++++++++++++-------- 1 file changed, 51 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c index 8d137857818c..174590f543c3 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c +++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c @@ -257,6 +257,7 @@ struct exynos_dsi { struct drm_connector connector; struct drm_panel *panel; struct list_head bridge_chain;

• struct drm_bridge bridge; struct drm_bridge *out_bridge; struct device *dev;

@@ -287,9 +288,9 @@ struct exynos_dsi { #define host_to_dsi(host) container_of(host, struct exynos_dsi, dsi_host) #define connector_to_dsi(c) container_of(c, struct exynos_dsi, connector)

-static inline struct exynos_dsi *encoder_to_dsi(struct drm_encoder *e) +static inline struct exynos_dsi *bridge_to_dsi(struct drm_bridge *b) {

• return container_of(e, struct exynos_dsi, encoder);

• return container_of(b, struct exynos_dsi, bridge); }

  enum reg_idx {

@@ -1374,9 +1375,10 @@ static void exynos_dsi_unregister_te_irq(struct exynos_dsi *dsi) } }

-static void exynos_dsi_enable(struct drm_encoder *encoder) +static void exynos_dsi_atomic_enable(struct drm_bridge *bridge,

• 		     struct drm_bridge_state *old_bridge_state)
  

  {

• struct exynos_dsi *dsi = encoder_to_dsi(encoder);

• struct exynos_dsi *dsi = bridge_to_dsi(bridge); struct drm_bridge *iter; int ret;

@@ -1399,7 +1401,8 @@ static void exynos_dsi_enable(struct drm_encoder *encoder) list_for_each_entry_reverse(iter, &dsi->bridge_chain, chain_node) { if (iter->funcs->pre_enable)

• 		iter->funcs->pre_enable(iter);
  

• 		iter->funcs->atomic_pre_enable(iter,
  

• 					       old_bridge_state);
  

  } }

@@ -1413,7 +1416,7 @@ static void exynos_dsi_enable(struct drm_encoder *encoder) } else { list_for_each_entry(iter, &dsi->bridge_chain, chain_node) { if (iter->funcs->enable)

• 		iter->funcs->enable(iter);
  

• 		iter->funcs->atomic_enable(iter, old_bridge_state);
  

  } }

@@ -1429,9 +1432,10 @@ static void exynos_dsi_enable(struct drm_encoder *encoder) pm_runtime_put(dsi->dev); }

-static void exynos_dsi_disable(struct drm_encoder *encoder) +static void exynos_dsi_atomic_disable(struct drm_bridge *bridge,

• 		      struct drm_bridge_state *old_bridge_state)
  

  {

• struct exynos_dsi *dsi = encoder_to_dsi(encoder);

• struct exynos_dsi *dsi = bridge_to_dsi(bridge); struct drm_bridge *iter;

  if (!(dsi->state & DSIM_STATE_ENABLED))

@@ -1443,7 +1447,7 @@ static void exynos_dsi_disable(struct drm_encoder *encoder)

list_for_each_entry_reverse(iter, &dsi->bridge_chain, chain_node) { if (iter->funcs->disable)

• 	iter->funcs->disable(iter);
  

• 	iter->funcs->atomic_disable(iter, old_bridge_state);
  

  }

  exynos_dsi_set_display_enable(dsi, false);

@@ -1451,7 +1455,7 @@ static void exynos_dsi_disable(struct drm_encoder *encoder)

list_for_each_entry(iter, &dsi->bridge_chain, chain_node) { if (iter->funcs->post_disable)

• 	iter->funcs->post_disable(iter);
  

• 	iter->funcs->atomic_post_disable(iter, old_bridge_state);
  

  }

  dsi->state &= ~DSIM_STATE_ENABLED;

@@ -1494,9 +1498,9 @@ static const struct drm_connector_helper_funcs exynos_dsi_connector_helper_funcs .get_modes = exynos_dsi_get_modes, };

-static int exynos_dsi_create_connector(struct drm_encoder *encoder) +static int exynos_dsi_create_connector(struct exynos_dsi *dsi) {

• struct exynos_dsi *dsi = encoder_to_dsi(encoder);

• struct drm_encoder *encoder = &dsi->encoder; struct drm_connector *connector = &dsi->connector; struct drm_device *drm = encoder->dev; int ret;

@@ -1522,9 +1526,21 @@ static int exynos_dsi_create_connector(struct drm_encoder *encoder) return 0; }

-static const struct drm_encoder_helper_funcs exynos_dsi_encoder_helper_funcs = {

• .enable = exynos_dsi_enable,
• .disable = exynos_dsi_disable,

+static int exynos_dsi_attach(struct drm_bridge *bridge,

• 	     enum drm_bridge_attach_flags flags)
  

+{

• struct exynos_dsi *dsi = bridge_to_dsi(bridge);
• return drm_bridge_attach(bridge->encoder, dsi->out_bridge, NULL, 0);

+}

+static const struct drm_bridge_funcs exynos_dsi_bridge_funcs = {

• .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,

• .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,

• .atomic_reset = drm_atomic_helper_bridge_reset,

• .atomic_enable = exynos_dsi_atomic_enable,

• .atomic_disable = exynos_dsi_atomic_disable,

• .attach = exynos_dsi_attach, };

  MODULE_DEVICE_TABLE(of, exynos_dsi_of_match);

@@ -1543,7 +1559,7 @@ static int exynos_dsi_host_attach(struct mipi_dsi_host *host, dsi->out_bridge = out_bridge; list_splice_init(&encoder->bridge_chain, &dsi->bridge_chain); } else {

• int ret = exynos_dsi_create_connector(encoder);
  

• int ret = exynos_dsi_create_connector(dsi);
  
  

  if (ret) { DRM_DEV_ERROR(dsi->dev,

@@ -1596,7 +1612,7 @@ static int exynos_dsi_host_detach(struct mipi_dsi_host *host,

if (dsi->panel) { mutex_lock(&drm->mode_config.mutex);

• exynos_dsi_disable(&dsi->encoder);
  

• exynos_dsi_atomic_disable(&dsi->bridge, NULL);
  

  dsi->panel = NULL; dsi->connector.status = connector_status_disconnected; mutex_unlock(&drm->mode_config.mutex);

@@ -1702,12 +1718,16 @@ static int exynos_dsi_bind(struct device *dev, struct device *master,

drm_simple_encoder_init(drm_dev, encoder, DRM_MODE_ENCODER_TMDS);

• drm_encoder_helper_add(encoder, &exynos_dsi_encoder_helper_funcs);
• ret = exynos_drm_set_possible_crtcs(encoder, EXYNOS_DISPLAY_TYPE_LCD); if (ret < 0) return ret;

• ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL, 0);
• if (ret) {

• drm_encoder_cleanup(&dsi->encoder);
  

• return ret;
  

• }
• in_bridge_node = of_graph_get_remote_node(dev->of_node, DSI_PORT_IN, 0); if (in_bridge_node) { in_bridge = of_drm_find_bridge(in_bridge_node);

@@ -1723,10 +1743,9 @@ static void exynos_dsi_unbind(struct device *dev, struct device *master, void *data) { struct exynos_dsi *dsi = dev_get_drvdata(dev);

• struct drm_encoder *encoder = &dsi->encoder;
• exynos_dsi_disable(encoder);

• exynos_dsi_atomic_disable(&dsi->bridge, NULL);
• drm_encoder_cleanup(&dsi->encoder); mipi_dsi_host_unregister(&dsi->dsi_host); }

@@ -1819,6 +1838,12 @@ static int exynos_dsi_probe(struct platform_device *pdev)

pm_runtime_enable(dev);

• dsi->bridge.funcs = &exynos_dsi_bridge_funcs;
• dsi->bridge.of_node = dev->of_node;
• dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
• drm_bridge_add(&dsi->bridge);
• ret = component_add(dev, &exynos_dsi_component_ops); if (ret) goto err_disable_runtime;

@@ -1833,6 +1858,10 @@ static int exynos_dsi_probe(struct platform_device *pdev)

static int exynos_dsi_remove(struct platform_device *pdev) {

• struct exynos_dsi *dsi = platform_get_drvdata(pdev);

• drm_bridge_remove(&dsi->bridge);

• pm_runtime_disable(&pdev->dev);

  component_del(&pdev->dev, &exynos_dsi_component_ops);

Best regards