Applied "spi: fsl-espi: extend and improve transfer error handling" to the spi tree

Commit Message

Mark Brown Oct. 28, 2016, 6:52 p.m. UTC

The patch

   spi: fsl-espi: extend and improve transfer error handling

has been applied to the spi tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

From db1b049fad8b12062edffade8272d604b4019eb7 Mon Sep 17 00:00:00 2001
From: Heiner Kallweit <[e-mail]>
Date: Thu, 27 Oct 2016 21:28:02 +0200
Subject: [PATCH] spi: fsl-espi: extend and improve transfer error handling

Extend and improve transfer error handling
- in case of timeout report also number of remaining rx bytes
- in case of timeout return ETIMEDOUT instead of EMSGSIZE
- add sanity checks after all bytes have been sent / read:
 - check that HW has flag SPIE_DON set
 - check that RX / TX FIFO are empty

Signed-off-by: Heiner Kallweit <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>
---
 drivers/spi/spi-fsl-espi.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

Patch

diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c
index d5506852e63c..a9593f9691ec 100644
--- a/drivers/spi/spi-fsl-espi.c
+++ b/drivers/spi/spi-fsl-espi.c
@@ -289,13 +289,13 @@  static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t)
 	ret = wait_for_completion_timeout(&mpc8xxx_spi->done, 2 * HZ);
 	if (ret == 0)
 		dev_err(mpc8xxx_spi->dev,
-			"Transaction hanging up (left %u bytes)\n",
-			mpc8xxx_spi->tx_len);
+			"Transaction hanging up (left %u tx bytes, %u rx bytes)\n",
+			mpc8xxx_spi->tx_len, mpc8xxx_spi->rx_len);
 
 	/* disable rx ints */
 	fsl_espi_write_reg(mpc8xxx_spi, ESPI_SPIM, 0);
 
-	return mpc8xxx_spi->tx_len > 0 ? -EMSGSIZE : 0;
+	return ret == 0 ? -ETIMEDOUT : 0;
 }
 
 static int fsl_espi_trans(struct spi_message *m, struct spi_transfer *trans)
@@ -469,8 +469,20 @@  static void fsl_espi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events)
 	if (mspi->tx_len)
 		fsl_espi_fill_tx_fifo(mspi, events);
 
-	if (!mspi->tx_len && !mspi->rx_len)
-		complete(&mspi->done);
+	if (mspi->tx_len || mspi->rx_len)
+		return;
+
+	/* we're done, but check for errors before returning */
+	events = fsl_espi_read_reg(mspi, ESPI_SPIE);
+
+	if (!(events & SPIE_DON))
+		dev_err(mspi->dev,
+			"Transfer done but SPIE_DON isn't set!\n");
+
+	if (SPIE_RXCNT(events) || SPIE_TXCNT(events) != FSL_ESPI_FIFO_SIZE)
+		dev_err(mspi->dev, "Transfer done but rx/tx fifo's aren't empty!\n");
+
+	complete(&mspi->done);
 }
 
 static irqreturn_t fsl_espi_irq(s32 irq, void *context_data)