Re: [Patch v2] spi: qup: Fix incorrect block transfers

From: Ivan T. Ivanov
Date: Tue Sep 30 2014 - 08:28:03 EST



Hi Andy, just few comments.

On Wed, 2014-09-24 at 16:04 -0500, Andy Gross wrote:

<snip>

> +static void spi_qup_fifo_read(struct spi_qup *controller,
> + struct spi_transfer *xfer)
> +{
> + u32 data;
> +
> + /* clear service request */
> + writel_relaxed(QUP_OP_IN_SERVICE_FLAG,
> + controller->base + QUP_OPERATIONAL);
> +

Please, could you indent function parameters to open brace, when
they can not fit into one line.

> + while (controller->rx_bytes < xfer->len) {
> + if (!(readl_relaxed(controller->base + QUP_OPERATIONAL) &
> + QUP_OP_IN_FIFO_NOT_EMPTY))

Should be aligned just after first open brace.

> + break;
> +
> + data = readl_relaxed(controller->base + QUP_INPUT_FIFO);
> +
> + spi_qup_fill_read_buffer(controller, xfer, data);
> }
> }
>

> +static void spi_qup_block_read(struct spi_qup *controller,
> + struct spi_transfer *xfer)
> +{
> + u32 data;
> + u32 words_per_blk = controller->in_blk_sz >> 2;

I have been confused from the variable name. These are number of
32 bits reads, not SPI words, right?

> + u32 num_words = (xfer->len - controller->rx_bytes) / controller->w_size;
> + int i;
> +
> + do {
> + /* ACK by clearing service flag */
> + writel_relaxed(QUP_OP_IN_SERVICE_FLAG,
> + controller->base + QUP_OPERATIONAL);
> +
> + /* transfer up to a block size of data in a single pass */
> + for (i = 0; num_words && i < words_per_blk; i++, num_words--) {
> +
> + /* read data and fill up rx buffer */
> + data = readl_relaxed(controller->base + QUP_INPUT_FIFO);
> + spi_qup_fill_read_buffer(controller, xfer, data);
> }
>
> - writel_relaxed(word, controller->base + QUP_OUTPUT_FIFO);
> - }
> + /* check to see if next block is ready */
> + if (!(readl_relaxed(controller->base + QUP_OPERATIONAL) &
> + QUP_OP_IN_BLOCK_READ_REQ))
> + break;
> +
> + } while (num_words);
> +
> + /*
> + * Due to extra stickiness of the QUP_OP_IN_SERVICE_FLAG during block
> + * reads, it has to be cleared again at the very end
> + */
> + if (readl_relaxed(controller->base + QUP_OPERATIONAL) &
> + QUP_OP_MAX_INPUT_DONE_FLAG)
> + writel_relaxed(QUP_OP_IN_SERVICE_FLAG,
> + controller->base + QUP_OPERATIONAL);
> +
> +}
> +
>
> static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
> @@ -285,9 +370,9 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
>
> writel_relaxed(qup_err, controller->base + QUP_ERROR_FLAGS);
> writel_relaxed(spi_err, controller->base + SPI_ERROR_FLAGS);
> - writel_relaxed(opflags, controller->base + QUP_OPERATIONAL);
>
> if (!xfer) {
> + writel_relaxed(opflags, controller->base + QUP_OPERATIONAL);
> dev_err_ratelimited(controller->dev, "unexpected irq %08x %08x %08x\n",
> qup_err, spi_err, opflags);
> return IRQ_HANDLED;
> @@ -315,11 +400,19 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
> error = -EIO;
> }
>
> - if (opflags & QUP_OP_IN_SERVICE_FLAG)
> - spi_qup_fifo_read(controller, xfer);
> + if (opflags & QUP_OP_IN_SERVICE_FLAG) {
> + if (opflags & QUP_OP_IN_BLOCK_READ_REQ)
> + spi_qup_block_read(controller, xfer);
> + else
> + spi_qup_fifo_read(controller, xfer);
> + }
>
> - if (opflags & QUP_OP_OUT_SERVICE_FLAG)
> - spi_qup_fifo_write(controller, xfer);
> + if (opflags & QUP_OP_OUT_SERVICE_FLAG) {
> + if (opflags & QUP_OP_OUT_BLOCK_WRITE_REQ)
> + spi_qup_block_write(controller, xfer);
> + else
> + spi_qup_fifo_write(controller, xfer,1);
> + }

ERROR: space required after that ',' (ctx:VxV)
#414: FILE: drivers/spi/spi-qup.c:414:
+ spi_qup_fifo_write(controller, xfer,1);
^

You don't really need this last parameter, right?

Regards,
Ivan

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