dmaengine: jz4780: Fix error handling/signedness issues

There are a some signedness bugs such as testing for < 0 on unsigned
return values. Additionally there are some cases where functions which
should return NULL on error actually return a PTR_ERR value which can
result in oopses on error. Fix these issues.

Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: dmaengine@vger.kernel.org
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 17 insertions, 16 deletions

diff --git a/drivers/dma/dma-jz4780.c b/drivers/dma/dma-jz4780.c
index 7af886fc47af..e4a291c67e2a 100644
--- a/drivers/dma/dma-jz4780.c
+++ b/drivers/dma/dma-jz4780.c
@@ -250,7 +250,7 @@ static uint32_t jz4780_dma_transfer_size(unsigned long val, uint32_t *shift)
         }
 }
 
-static uint32_t jz4780_dma_setup_hwdesc(struct jz4780_dma_chan *jzchan,
+static int jz4780_dma_setup_hwdesc(struct jz4780_dma_chan *jzchan,
         struct jz4780_dma_hwdesc *desc, dma_addr_t addr, size_t len,
         enum dma_transfer_direction direction)
 {
@@ -301,6 +301,7 @@ static uint32_t jz4780_dma_setup_hwdesc(struct jz4780_dma_chan *jzchan,
         desc->dcm |= width << JZ_DMA_DCM_DP_SHIFT;
 
         desc->dtc = len >> jzchan->transfer_shift;
+        return 0;
 }
 
 static struct dma_async_tx_descriptor *jz4780_dma_prep_slave_sg(
@@ -319,12 +320,11 @@ static struct dma_async_tx_descriptor *jz4780_dma_prep_slave_sg(
 
         for (i = 0; i < sg_len; i++) {
                 err = jz4780_dma_setup_hwdesc(jzchan, &desc->desc[i],
-                                        sg_dma_address(&sgl[i]),
-                                        sg_dma_len(&sgl[i]),
-                                        direction);
+                                              sg_dma_address(&sgl[i]),
+                                              sg_dma_len(&sgl[i]),
+                                              direction);
                 if (err < 0)
-                        return ERR_PTR(err);
-
+                        return NULL;
 
                 desc->desc[i].dcm |= JZ_DMA_DCM_TIE;
 
@@ -366,9 +366,9 @@ static struct dma_async_tx_descriptor *jz4780_dma_prep_dma_cyclic(
 
         for (i = 0; i < periods; i++) {
                 err = jz4780_dma_setup_hwdesc(jzchan, &desc->desc[i], buf_addr,
-                                        period_len, direction);
+                                              period_len, direction);
                 if (err < 0)
-                        return ERR_PTR(err);
+                        return NULL;
 
                 buf_addr += period_len;
 
@@ -417,7 +417,7 @@ struct dma_async_tx_descriptor *jz4780_dma_prep_dma_memcpy(
                             tsz << JZ_DMA_DCM_TSZ_SHIFT |
                             JZ_DMA_WIDTH_32_BIT << JZ_DMA_DCM_SP_SHIFT |
                             JZ_DMA_WIDTH_32_BIT << JZ_DMA_DCM_DP_SHIFT;
-        desc->desc[0].dtc = len >> ord;
+        desc->desc[0].dtc = len >> jzchan->transfer_shift;
 
         return vchan_tx_prep(&jzchan->vchan, &desc->vdesc, flags);
 }
@@ -580,8 +580,8 @@ static enum dma_status jz4780_dma_tx_status(struct dma_chan *chan,
                 txstate->residue = 0;
 
         if (vdesc && jzchan->desc && vdesc == &jzchan->desc->vdesc
-                && jzchan->desc->status & (JZ_DMA_DCS_AR | JZ_DMA_DCS_HLT))
-                        status = DMA_ERROR;
+            && jzchan->desc->status & (JZ_DMA_DCS_AR | JZ_DMA_DCS_HLT))
+                status = DMA_ERROR;
 
         spin_unlock_irqrestore(&jzchan->vchan.lock, flags);
         return status;
@@ -756,17 +756,19 @@ static int jz4780_dma_probe(struct platform_device *pdev)
         if (IS_ERR(jzdma->base))
                 return PTR_ERR(jzdma->base);
 
-        jzdma->irq = platform_get_irq(pdev, 0);
-        if (jzdma->irq < 0) {
+        ret = platform_get_irq(pdev, 0);
+        if (ret < 0) {
                 dev_err(dev, "failed to get IRQ: %d\n", ret);
-                return jzdma->irq;
+                return ret;
         }
 
+        jzdma->irq = ret;
+
         ret = devm_request_irq(dev, jzdma->irq, jz4780_dma_irq_handler, 0,
                                dev_name(dev), jzdma);
         if (ret) {
                 dev_err(dev, "failed to request IRQ %u!\n", jzdma->irq);
-                return -EINVAL;
+                return ret;
         }
 
         jzdma->clk = devm_clk_get(dev, NULL);
@@ -803,7 +805,6 @@ static int jz4780_dma_probe(struct platform_device *pdev)
         dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
         dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
 
-
         /*
          * Enable DMA controller, mark all channels as not programmable.
          * Also set the FMSC bit - it increases MSC performance, so it makes