drm/loongson: Fix error handling in lsdc_pixel_pll_setup()

[ Upstream commit 5976a28b344ecb6810882a01b76a320cac21d307 ]

There are two problems in lsdc_pixel_pll_setup()
1. If kzalloc() fails then call iounmap() to release the resources.
2. Both kzalloc and ioremap does not return error pointers on failure, so
   using IS_ERR_OR_NULL() checks is a bit confusing and not very right,
   fix this by changing those to NULL checks instead.

Fixes: f39db26c5428 ("drm: Add kms driver for loongson display controller")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn>
Signed-off-by: Sui Jingfeng <sui.jingfeng@linux.dev>
Link: https://patchwork.freedesktop.org/patch/msgid/20230720123950.543082-1-harshit.m.mogalapalli@oracle.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/loongson/lsdc_pixpll.c b/drivers/gpu/drm/loongson/lsdc_pixpll.c
index 04c15b4..2609a22 100644 (file)
--- a/drivers/gpu/drm/loongson/lsdc_pixpll.c
+++ b/drivers/gpu/drm/loongson/lsdc_pixpll.c
@@ -120,12 +120,14 @@ static int lsdc_pixel_pll_setup(struct lsdc_pixpll * const this)
        struct lsdc_pixpll_parms *pparms;
 
        this->mmio = ioremap(this->reg_base, this->reg_size);
-       if (IS_ERR_OR_NULL(this->mmio))
+       if (!this->mmio)
                return -ENOMEM;
 
        pparms = kzalloc(sizeof(*pparms), GFP_KERNEL);
-       if (IS_ERR_OR_NULL(pparms))
+       if (!pparms) {
+               iounmap(this->mmio);
                return -ENOMEM;
+       }
 
        pparms->ref_clock = LSDC_PLL_REF_CLK_KHZ;