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Unverified Commit a75e91ba authored by Jorge Ramirez-Ortiz's avatar Jorge Ramirez-Ortiz Committed by Mark Brown
Browse files

spi: qup: fix PIO/DMA transfers. 



- DMA/PIO:
  If an error IRQ occurred during PIO or DMA mode make sure to log it so
on completion the transfer can be marked as an error.

- PIO:
  Do not complete a transaction until all data has been transferred or
an error IRQ was flagged.

1) If there was no error IRQ, ignore the done flag IRQ
(QUP_OP_MAX_INPUT_DONE_FLAG) until all data for the transfer has been
processed: not doing so risks completing the transfer returning
uninitialized data in the buffers.

2) Under stress testing we have identified the need to
protect read/write operations against spurious IN/OUT service events.

Signed-off-by: default avatarJorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent f3440d9a

drivers/spi/spi-qup.c

+45 −6
Original line number Diff line number Diff line
@@ -281,6 +281,9 @@ static void spi_qup_read(struct spi_qup *controller, u32 *opflags) 
		writel_relaxed(QUP_OP_IN_SERVICE_FLAG,

			       controller->base + QUP_OPERATIONAL);



		if (!remainder)

			goto exit;



		if (is_block_mode) {

			num_words = (remainder > words_per_block) ?

					words_per_block : remainder;
@@ -310,11 +313,13 @@ static void spi_qup_read(struct spi_qup *controller, u32 *opflags) 
	 * to refresh opflags value because MAX_INPUT_DONE_FLAG may now be

	 * present and this is used to determine if transaction is complete

	 */

exit:

	if (!remainder) {

		*opflags = readl_relaxed(controller->base + QUP_OPERATIONAL);

		if (is_block_mode && *opflags & QUP_OP_MAX_INPUT_DONE_FLAG)

			writel_relaxed(QUP_OP_IN_SERVICE_FLAG,

				       controller->base + QUP_OPERATIONAL);



	}

}



static void spi_qup_write_to_fifo(struct spi_qup *controller, u32 num_words)
@@ -362,6 +367,10 @@ static void spi_qup_write(struct spi_qup *controller) 
		writel_relaxed(QUP_OP_OUT_SERVICE_FLAG,

			       controller->base + QUP_OPERATIONAL);



		/* make sure the interrupt is valid */

		if (!remainder)

			return;



		if (is_block_mode) {

			num_words = (remainder > words_per_block) ?

				words_per_block : remainder;
@@ -575,10 +584,24 @@ static int spi_qup_do_pio(struct spi_device *spi, struct spi_transfer *xfer, 
	return 0;

}



static bool spi_qup_data_pending(struct spi_qup *controller)

{

	unsigned int remainder_tx, remainder_rx;



	remainder_tx = DIV_ROUND_UP(spi_qup_len(controller) -

				    controller->tx_bytes, controller->w_size);



	remainder_rx = DIV_ROUND_UP(spi_qup_len(controller) -

				    controller->rx_bytes, controller->w_size);



	return remainder_tx || remainder_rx;

}



static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)

{

	struct spi_qup *controller = dev_id;

	u32 opflags, qup_err, spi_err;

	unsigned long flags;

	int error = 0;



	qup_err = readl_relaxed(controller->base + QUP_ERROR_FLAGS);
@@ -610,6 +633,11 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id) 
		error = -EIO;

	}



	spin_lock_irqsave(&controller->lock, flags);

	if (!controller->error)

		controller->error = error;

	spin_unlock_irqrestore(&controller->lock, flags);



	if (spi_qup_is_dma_xfer(controller->mode)) {

		writel_relaxed(opflags, controller->base + QUP_OPERATIONAL);

	} else {
@@ -618,11 +646,22 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id) 


		if (opflags & QUP_OP_OUT_SERVICE_FLAG)

			spi_qup_write(controller);



		if (!spi_qup_data_pending(controller))

			complete(&controller->done);

	}



	if ((opflags & QUP_OP_MAX_INPUT_DONE_FLAG) || error)

	if (error)

		complete(&controller->done);



	if (opflags & QUP_OP_MAX_INPUT_DONE_FLAG) {

		if (!spi_qup_is_dma_xfer(controller->mode)) {

			if (spi_qup_data_pending(controller))

				return IRQ_HANDLED;

		}

		complete(&controller->done);

	}



	return IRQ_HANDLED;

}