Re: [PATCH next] drm/loongson: Fix error handling in lsdc_pixel_pll_setup()

[suijingfeng]

Hi,


On 2023/7/20 20:39, Harshit Mogalapalli wrote:

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 doesnot 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.mogalapa...@oracle.com>

Reviewed-by: Sui Jingfeng <suijingf...@loongson.cn>

---
This is found with static analysis with smacth and only compile tested.
---
  drivers/gpu/drm/loongson/lsdc_pixpll.c | 6 ++++--
  1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/loongson/lsdc_pixpll.c 
b/drivers/gpu/drm/loongson/lsdc_pixpll.c
index 04c15b4697e2..2609a2256da4 100644
--- 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;