Hi Dan,
It is for avoiding the last char of newline. I will change it.
Thanks,
Eric
On 16-05-10 06:51 AM, Dan Carpenter wrote:
> Hello Eric Huang,
>
> The patch 5632708f4452: "drm/amd/powerplay: add dpm force multiple
> levels on cz/tonga/fiji/polaris (v2)" from Apr 12, 2016, leads to the
> following static checker warning:
>
> drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c:368 amdgpu_set_pp_dpm_sclk()
> warn: why is the last element skipped?
>
> drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
> 356 static ssize_t amdgpu_set_pp_dpm_sclk(struct device *dev,
> 357 struct device_attribute *attr,
> 358 const char *buf,
> 359 size_t count)
> 360 {
> 361 struct drm_device *ddev = dev_get_drvdata(dev);
> 362 struct amdgpu_device *adev = ddev->dev_private;
> 363 int ret;
> 364 long level;
> 365 uint32_t i, mask = 0;
> 366 char sub_str[2];
> 367
> 368 for (i = 0; i < strlen(buf) - 1; i++) {
>
> strlen() returns the number of characters not counting the NUL
> terminator. I guess this assumes that the last character is a newline?
> Could we check for that instead?
>
> 369 sub_str[0] = *(buf + i);
> 370 sub_str[1] = '\0';
> 371 ret = kstrtol(sub_str, 0, &level);
> 372
> 373 if (ret) {
> 374 count = -EINVAL;
> 375 goto fail;
> 376 }
> 377 mask |= 1 << level;
> 378 }
> 379
> 380 if (adev->pp_enabled)
> 381 amdgpu_dpm_force_clock_level(adev, PP_SCLK, mask);
> 382 fail:
> 383 return count;
> 384 }
>
> There are a couple other:
> drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c:412 amdgpu_set_pp_dpm_mclk() warn: why
> is the last element skipped?
> drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c:456 amdgpu_set_pp_dpm_pcie() warn: why
> is the last element skipped?
>
> regards,
> dan carpenter
