Re: [PATCH 05/52] drm/mipi_dbi: Use drmm_add_final_kfree in all drivers

Hi Daniel,

good idea. I guess it's the simple encoder's fault. :) I only read briefly over the whole thing.

Am 19.02.20 um 11:20 schrieb Daniel Vetter:

They all share mipi_dbi_release so we need to switch them all together. With this we can drop the final kfree from the release function.

Aside, I think we could perhaps have a tiny additional helper for these mipi_dbi drivers, the first few lines around devm_drm_dev_init are all the same (except for the drm_driver pointer).

Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com Cc: Maxime Ripard mripard@kernel.org Cc: Thomas Zimmermann tzimmermann@suse.de Cc: David Airlie airlied@linux.ie Cc: Daniel Vetter daniel@ffwll.ch Cc: Eric Anholt eric@anholt.net Cc: David Lechner david@lechnology.com Cc: Kamlesh Gurudasani kamlesh.gurudasani@gmail.com Cc: "Noralf Trønnes" noralf@tronnes.org Cc: Sam Ravnborg sam@ravnborg.org Signed-off-by: Daniel Vetter daniel.vetter@intel.com

---

drivers/gpu/drm/drm_mipi_dbi.c | 3 --- drivers/gpu/drm/tiny/hx8357d.c | 2 ++ drivers/gpu/drm/tiny/ili9225.c | 2 ++ drivers/gpu/drm/tiny/ili9341.c | 2 ++ drivers/gpu/drm/tiny/ili9486.c | 2 ++ drivers/gpu/drm/tiny/mi0283qt.c | 2 ++ drivers/gpu/drm/tiny/st7586.c | 2 ++ drivers/gpu/drm/tiny/st7735r.c | 2 ++ 8 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_mipi_dbi.c b/drivers/gpu/drm/drm_mipi_dbi.c index 558baf989f5a..069603dfcd10 100644 --- a/drivers/gpu/drm/drm_mipi_dbi.c +++ b/drivers/gpu/drm/drm_mipi_dbi.c @@ -588,13 +588,10 @@ EXPORT_SYMBOL(mipi_dbi_dev_init); */ void mipi_dbi_release(struct drm_device *drm) {

• struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(drm);

• DRM_DEBUG_DRIVER("\n");

  drm_mode_config_cleanup(drm); drm_dev_fini(drm);

• kfree(dbidev);

} EXPORT_SYMBOL(mipi_dbi_release);

diff --git a/drivers/gpu/drm/tiny/hx8357d.c b/drivers/gpu/drm/tiny/hx8357d.c index 9af8ff84974f..42bc5dadcb1c 100644 --- a/drivers/gpu/drm/tiny/hx8357d.c +++ b/drivers/gpu/drm/tiny/hx8357d.c @@ -21,6 +21,7 @@ #include <drm/drm_fb_helper.h> #include <drm/drm_gem_cma_helper.h> #include <drm/drm_gem_framebuffer_helper.h> +#include <drm/drm_managed.h> #include <drm/drm_mipi_dbi.h> #include <drm/drm_modeset_helper.h> #include <video/mipi_display.h> @@ -236,6 +237,7 @@ static int hx8357d_probe(struct spi_device *spi) kfree(dbidev); return ret; }

• drmm_add_final_kfree(drm, dbidev);

I'd prefer something else than drmm_add_final_kfree().

From what I understand, drmmadd_add_final_kfree() is required so that the device instance itself gets free. But wiring up garbage collection manually is easy to forget and a somewhat odd design. If we have to do that, there's little benefit over calling kfree in the release callback.

Instead, could drivers rather be converted to drm_dev_alloc() where possible?

For the other cases, could there be a dedicated allocator function that invokes drmm_add_final_kfree()? Like that

void* __drmm_kzalloc_dev(size_t size, size_t dev_off) { void *parent = kzalloc(size)

drm_device *dev = (parent + dev_off)

__drmm_add_final_kfree(dev, parent);

return parent; }

/* * takes the name of driver's device structure and the * name of the drm device structure embedded within */ drmm_kzalloc(parent_type, base) (parent_type*)__drm_kzalloc_dev(sizeof(parent_type), offsetof(parent_type, base));

Best regards Thomas

drm_mode_config_init(drm);

diff --git a/drivers/gpu/drm/tiny/ili9225.c b/drivers/gpu/drm/tiny/ili9225.c index 802fb8dde1b6..aae88dc5b3f7 100644 --- a/drivers/gpu/drm/tiny/ili9225.c +++ b/drivers/gpu/drm/tiny/ili9225.c @@ -24,6 +24,7 @@ #include <drm/drm_fourcc.h> #include <drm/drm_gem_cma_helper.h> #include <drm/drm_gem_framebuffer_helper.h> +#include <drm/drm_managed.h> #include <drm/drm_mipi_dbi.h> #include <drm/drm_rect.h>

@@ -387,6 +388,7 @@ static int ili9225_probe(struct spi_device *spi) kfree(dbidev); return ret; }

• drmm_add_final_kfree(drm, dbidev);

  drm_mode_config_init(drm);

diff --git a/drivers/gpu/drm/tiny/ili9341.c b/drivers/gpu/drm/tiny/ili9341.c index 33b51dc7faa8..7d40cb4ff72b 100644 --- a/drivers/gpu/drm/tiny/ili9341.c +++ b/drivers/gpu/drm/tiny/ili9341.c @@ -20,6 +20,7 @@ #include <drm/drm_fb_helper.h> #include <drm/drm_gem_cma_helper.h> #include <drm/drm_gem_framebuffer_helper.h> +#include <drm/drm_managed.h> #include <drm/drm_mipi_dbi.h> #include <drm/drm_modeset_helper.h> #include <video/mipi_display.h> @@ -194,6 +195,7 @@ static int ili9341_probe(struct spi_device *spi) kfree(dbidev); return ret; }

• drmm_add_final_kfree(drm, dbidev);

  drm_mode_config_init(drm);

diff --git a/drivers/gpu/drm/tiny/ili9486.c b/drivers/gpu/drm/tiny/ili9486.c index 5084b38c1a71..7d735fc67498 100644 --- a/drivers/gpu/drm/tiny/ili9486.c +++ b/drivers/gpu/drm/tiny/ili9486.c @@ -19,6 +19,7 @@ #include <drm/drm_fb_helper.h> #include <drm/drm_gem_cma_helper.h> #include <drm/drm_gem_framebuffer_helper.h> +#include <drm/drm_managed.h> #include <drm/drm_mipi_dbi.h> #include <drm/drm_modeset_helper.h>

@@ -208,6 +209,7 @@ static int ili9486_probe(struct spi_device *spi) kfree(dbidev); return ret; }

• drmm_add_final_kfree(drm, dbidev);

  drm_mode_config_init(drm);

diff --git a/drivers/gpu/drm/tiny/mi0283qt.c b/drivers/gpu/drm/tiny/mi0283qt.c index e2cfd9a17143..8555a56bce8c 100644 --- a/drivers/gpu/drm/tiny/mi0283qt.c +++ b/drivers/gpu/drm/tiny/mi0283qt.c @@ -18,6 +18,7 @@ #include <drm/drm_fb_helper.h> #include <drm/drm_gem_cma_helper.h> #include <drm/drm_gem_framebuffer_helper.h> +#include <drm/drm_managed.h> #include <drm/drm_mipi_dbi.h> #include <drm/drm_modeset_helper.h> #include <video/mipi_display.h> @@ -198,6 +199,7 @@ static int mi0283qt_probe(struct spi_device *spi) kfree(dbidev); return ret; }

• drmm_add_final_kfree(drm, dbidev);

  drm_mode_config_init(drm);

diff --git a/drivers/gpu/drm/tiny/st7586.c b/drivers/gpu/drm/tiny/st7586.c index 9ef559dd3191..427c2561f5f4 100644 --- a/drivers/gpu/drm/tiny/st7586.c +++ b/drivers/gpu/drm/tiny/st7586.c @@ -21,6 +21,7 @@ #include <drm/drm_format_helper.h> #include <drm/drm_gem_cma_helper.h> #include <drm/drm_gem_framebuffer_helper.h> +#include <drm/drm_managed.h> #include <drm/drm_mipi_dbi.h> #include <drm/drm_rect.h>

@@ -328,6 +329,7 @@ static int st7586_probe(struct spi_device *spi) kfree(dbidev); return ret; }

• drmm_add_final_kfree(drm, dbidev);

  drm_mode_config_init(drm);

diff --git a/drivers/gpu/drm/tiny/st7735r.c b/drivers/gpu/drm/tiny/st7735r.c index 18b925df6e51..b447235c3d47 100644 --- a/drivers/gpu/drm/tiny/st7735r.c +++ b/drivers/gpu/drm/tiny/st7735r.c @@ -21,6 +21,7 @@ #include <drm/drm_fb_helper.h> #include <drm/drm_gem_cma_helper.h> #include <drm/drm_gem_framebuffer_helper.h> +#include <drm/drm_managed.h> #include <drm/drm_mipi_dbi.h>

#define ST7735R_FRMCTR1 0xb1 @@ -209,6 +210,7 @@ static int st7735r_probe(struct spi_device *spi) kfree(dbidev); return ret; }

• drmm_add_final_kfree(drm, dbidev);

  drm_mode_config_init(drm);