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>

diff --git a/drivers/dma/dma-jz4780.c b/drivers/dma/dma-jz4780.c
index 7af886fc47af974d846777f79b7beac17c176b33..e4a291c67e2a3257d607b8a4537dbcf503583c81 100644 (file)
--- 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