On Fri, Jun 23, 2017 at 10:58:16AM +0200, Stefan Roese wrote:
> +/* mSGDMA descriptor control field bit definitions */
> +#define MSGDMA_DESC_CTL_SET_CH(x) ((x) & 0xff)
> +#define MSGDMA_DESC_CTL_GEN_SOP BIT(8)
> +#define MSGDMA_DESC_CTL_GEN_EOP BIT(9)
> +#define MSGDMA_DESC_CTL_PARK_READS BIT(10)
> +#define MSGDMA_DESC_CTL_PARK_WRITES BIT(11)
> +#define MSGDMA_DESC_CTL_END_ON_EOP BIT(12)
> +#define MSGDMA_DESC_CTL_END_ON_LEN BIT(13)
> +#define MSGDMA_DESC_CTL_TR_COMP_IRQ BIT(14)
> +#define MSGDMA_DESC_CTL_EARLY_IRQ BIT(15)
> +#define MSGDMA_DESC_CTL_TR_ERR_IRQ (0xff << 16)
why can't this be expressed in GENMASK? GENMASK(23, 16)
> +/* mSGDMA response register bit definitions */
> +#define MSGDMA_RESP_EARLY_TERM BIT(8)
> +#define MSGDMA_RESP_ERR_MASK 0xFF
TABS or Spaces please, not both
> +static struct dma_async_tx_descriptor *
> +msgdma_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
> + unsigned int sg_len, enum dma_transfer_direction dir,
> + unsigned long flags, void *context)
> +
> +{
> + struct msgdma_device *mdev = to_mdev(dchan);
> + struct dma_slave_config *cfg = &mdev->slave_cfg;
> + struct msgdma_sw_desc *new, *first = NULL;
> + void *desc = NULL;
> + size_t len, avail;
> + dma_addr_t dma_dst, dma_src;
> + u32 desc_cnt = 0, i;
> + struct scatterlist *sg;
> + u32 stride;
> +
> + for_each_sg(sgl, sg, sg_len, i)
> + desc_cnt += DIV_ROUND_UP(sg_dma_len(sg), MSGDMA_MAX_TRANS_LEN);
> +
> + spin_lock_bh(&mdev->lock);
> + if (desc_cnt > mdev->desc_free_cnt) {
> + spin_unlock_bh(&mdev->lock);
> + dev_dbg(mdev->dev, "mdev %p descs are not available\n", mdev);
> + return NULL;
> + }
> + mdev->desc_free_cnt -= desc_cnt;
> + spin_unlock_bh(&mdev->lock);
> +
> + avail = sg_dma_len(sgl);
> +
> + /* Run until we are out of scatterlist entries */
> + while (true) {
> + /* Allocate and populate the descriptor */
> + new = msgdma_get_descriptor(mdev);
> +
> + desc = &new->hw_desc;
> + len = min_t(size_t, avail, MSGDMA_MAX_TRANS_LEN);
> + if (len == 0)
> + goto fetch;
can you explain this part, I typically dont like goto other than err
handling
> +static int msgdma_alloc_chan_resources(struct dma_chan *dchan)
> +{
> + struct msgdma_device *mdev = to_mdev(dchan);
> + struct msgdma_sw_desc *desc;
> + int i;
> +
> + mdev->sw_desq = kzalloc(sizeof(*desc) * MSGDMA_DESC_NUM, GFP_NOWAIT);
kcalloc perhpas
> +static irqreturn_t msgdma_irq_handler(int irq, void *data)
> +{
> + struct msgdma_device *mdev = data;
> + u32 status;
> +
> + status = ioread32(&mdev->csr->status);
> + if ((status & MSGDMA_CSR_STAT_BUSY) == 0)
> + mdev->idle = true;
> +
> + tasklet_schedule(&mdev->irq_tasklet);
> +
> + /* Clear interrupt in mSGDMA controller */
> + iowrite32(MSGDMA_CSR_STAT_IRQ, &mdev->csr->status);
> +
> + return IRQ_HANDLED;
are we not going to submit here :(
--
~Vinod
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