Hi

Am 15.12.21 um 10:51 schrieb Maxime Ripard:

If we have nomodeset on the kernel command line we should have the firmware framebuffer driver kept as is and not try to load the full-blown KMS driver.

In this case, let's just register the v3d driver.

Signed-off-by: Maxime Ripard maxime@cerno.tech

drivers/gpu/drm/vc4/vc4_drv.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c index 16abc3a3d601..d3cae84a4c4e 100644 --- a/drivers/gpu/drm/vc4/vc4_drv.c +++ b/drivers/gpu/drm/vc4/vc4_drv.c @@ -357,6 +357,9 @@ static int __init vc4_drm_register(void) { int ret;

• if (drm_firmware_drivers_only())

• return -ENODEV;
  

Just now that you've updated it, Lucas Stach had a similar concern about etnaviv, which doesn't do modesetting either. So we probably want to discuss what to do about drivers that have no modesetting separately.

If you want to land the patch, for either version of the code, with or without vc3:

Reviewed-by: Thomas Zimmermann tzimmermann@suse.de

Best regard Thomas

ret = platform_register_drivers(component_drivers, ARRAY_SIZE(component_drivers)); if (ret)

Hi

Am 15.12.21 um 10:51 schrieb Maxime Ripard:

Once the call to drm_fb_helper_remove_conflicting_framebuffers() has been made, simplefb has been unregistered and the KMS driver is entirely in charge of the display.

Thus, we can notify the firmware it can free whatever resource it was using to maintain simplefb functional.

Signed-off-by: Maxime Ripard maxime@cerno.tech

drivers/gpu/drm/vc4/vc4_drv.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)

diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c index 86c61ee120b7..a03053c8e22c 100644 --- a/drivers/gpu/drm/vc4/vc4_drv.c +++ b/drivers/gpu/drm/vc4/vc4_drv.c @@ -37,6 +37,8 @@ #include <drm/drm_fb_helper.h> #include <drm/drm_vblank.h>

+#include <soc/bcm2835/raspberrypi-firmware.h>

• #include "uapi/drm/vc4_drm.h"

  #include "vc4_drv.h"

@@ -215,6 +217,7 @@ static void vc4_match_add_drivers(struct device *dev, static int vc4_drm_bind(struct device *dev) { struct platform_device *pdev = to_platform_device(dev);

• struct rpi_firmware *firmware = NULL; struct drm_device *drm; struct vc4_dev *vc4; struct device_node *node;

@@ -251,10 +254,29 @@ static int vc4_drm_bind(struct device *dev) if (ret) return ret;

• node = of_find_compatible_node(NULL, NULL, "raspberrypi,bcm2835-firmware");
• if (node) {

• firmware = rpi_firmware_get(node);
  

• of_node_put(node);
  

• if (!firmware)
  

• 	return -EPROBE_DEFER;
  

• }

The code is

Acked-by: Thomas Zimmermann tzimmermann@suse.de

Just for my understanding:

You retrieve the firmware before killing simpledrm simply to keep the display on if it fails, right?

What's the possible error that would justify a retry (via EPROBE_DEFER)?

Best regards Thomas

ret = drm_aperture_remove_framebuffers(false, &vc4_drm_driver); if (ret) return ret;

• if (firmware) {

• ret = rpi_firmware_property(firmware,
  

• 			    RPI_FIRMWARE_NOTIFY_DISPLAY_DONE,
  

• 			    NULL, 0);
  

• if (ret)
  

• 	drm_warn(drm, "Couldn't stop firmware display driver: %d\n", ret);
  

• rpi_firmware_put(firmware);
  

• }
• ret = component_bind_all(dev, drm); if (ret) return ret;