[bug report] drm/msm/dpu: merge struct dpu_irq into struct dpu_hw_intr

[Dan Carpenter]

Hello Dmitry Baryshkov,

The patch f25f656608e3: "drm/msm/dpu: merge struct dpu_irq into
struct dpu_hw_intr" from Jun 18, 2021, leads to the following Smatch
static checker warnings:

drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c:569 dpu_core_irq_preinstall()
error: potential null dereference 'dpu_kms->hw_intr->irq_cb_tbl'.  (kcalloc returns null)

drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c:570 dpu_core_irq_preinstall()
error: potential null dereference 'dpu_kms->hw_intr->irq_counts'.  (kcalloc returns null)

drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c
    554 void dpu_core_irq_preinstall(struct dpu_kms *dpu_kms)
    555 {
    556         int i;
    557 
    558         pm_runtime_get_sync(&dpu_kms->pdev->dev);
    559         dpu_clear_irqs(dpu_kms);
    560         dpu_disable_all_irqs(dpu_kms);
    561         pm_runtime_put_sync(&dpu_kms->pdev->dev);
    562 
    563         /* Create irq callbacks for all possible irq_idx */
    564         dpu_kms->hw_intr->irq_cb_tbl = kcalloc(dpu_kms->hw_intr->total_irqs,
    565                         sizeof(struct list_head), GFP_KERNEL);
    566         dpu_kms->hw_intr->irq_counts = kcalloc(dpu_kms->hw_intr->total_irqs,
    567                         sizeof(atomic_t), GFP_KERNEL);

No checks for these kcallocs...  It's not actually new code but shuffling
them around makes them show up as new in my tests.

    568         for (i = 0; i < dpu_kms->hw_intr->total_irqs; i++) {
--> 569                 INIT_LIST_HEAD(&dpu_kms->hw_intr->irq_cb_tbl[i]);
    570                 atomic_set(&dpu_kms->hw_intr->irq_counts[i], 0);
    571         }
    572 }

regards,
dan carpenter