From d50f74790bbba662d1438dbc03be6616c52c0722 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Mon, 16 May 2022 15:43:38 +0200 Subject: [PATCH] drm/mgag200: Fail on I2C initialization errors Initialization of the I2C adapter was allowed to fail. The mgag200 driver would have continued without DDC support. Had this happened in practice, it would have led to segmentation faults in the connector code. Resolve this problem by failing driver initialization on I2C- related errors. v2: * initialize 'ret' before drm_err() (kernel test robot) Signed-off-by: Thomas Zimmermann Reviewed-by: Jocelyn Falempe Tested-by: Jocelyn Falempe Link: https://patchwork.freedesktop.org/patch/msgid/20220516134343.6085-3-tzimmermann@suse.de --- drivers/gpu/drm/mgag200/mgag200_i2c.c | 13 ++++++++----- drivers/gpu/drm/mgag200/mgag200_mode.c | 7 +++++-- 2 files changed, 13 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/mgag200/mgag200_i2c.c b/drivers/gpu/drm/mgag200/mgag200_i2c.c index ac8e34eef5138..31e2c641a7814 100644 --- a/drivers/gpu/drm/mgag200/mgag200_i2c.c +++ b/drivers/gpu/drm/mgag200/mgag200_i2c.c @@ -120,7 +120,7 @@ struct mga_i2c_chan *mgag200_i2c_create(struct drm_device *dev) i2c = kzalloc(sizeof(struct mga_i2c_chan), GFP_KERNEL); if (!i2c) - return NULL; + return ERR_PTR(-ENOMEM); i2c->data = data; i2c->clock = clock; @@ -142,11 +142,14 @@ struct mga_i2c_chan *mgag200_i2c_create(struct drm_device *dev) i2c->bit.getscl = mga_gpio_getscl; ret = i2c_bit_add_bus(&i2c->adapter); - if (ret) { - kfree(i2c); - i2c = NULL; - } + if (ret) + goto err_kfree; + return i2c; + +err_kfree: + kfree(i2c); + return ERR_PTR(ret); } void mgag200_i2c_destroy(struct mga_i2c_chan *i2c) diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c index 762b9657ae8d3..b227891d01ec7 100644 --- a/drivers/gpu/drm/mgag200/mgag200_mode.c +++ b/drivers/gpu/drm/mgag200/mgag200_mode.c @@ -849,8 +849,11 @@ static int mgag200_vga_connector_init(struct mga_device *mdev) int ret; i2c = mgag200_i2c_create(dev); - if (!i2c) - drm_warn(dev, "failed to add DDC bus\n"); + if (IS_ERR(i2c)) { + ret = PTR_ERR(i2c) + drm_err(dev, "failed to add DDC bus: %d\n", ret); + return ret; + } ret = drm_connector_init_with_ddc(dev, connector, &mga_vga_connector_funcs, -- 2.30.2