[PATCH v3 3/6] spi: sun6i: restrict transfer length in PIO-mode
From: Maxime Ripard <hidden>
Date: 2018-04-04 06:50:51
Also in:
linux-spi, lkml
On Tue, Apr 03, 2018 at 06:44:46PM +0300, Sergey Suloev wrote:
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There is no need to handle 3/4 empty interrupt as the maximum supported transfer length in PIO mode is equal to FIFO depth, i.e. 128 bytes for sun6i and 64 bytes for sun8i SoCs. Changes in v3: 1) Restored processing of 3/4 FIFO full interrupt. Signed-off-by: Sergey Suloev <redacted> --- drivers/spi/spi-sun6i.c | 41 +++++++++++++++++------------------------ 1 file changed, 17 insertions(+), 24 deletions(-)diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c index 78acc1f..c09ad10 100644 --- a/drivers/spi/spi-sun6i.c +++ b/drivers/spi/spi-sun6i.c@@ -207,7 +207,10 @@ static void sun6i_spi_set_cs(struct spi_device *spi, bool enable) static size_t sun6i_spi_max_transfer_size(struct spi_device *spi) { - return SUN6I_MAX_XFER_SIZE - 1; + struct spi_master *master = spi->master; + struct sun6i_spi *sspi = spi_master_get_devdata(master); + + return sspi->fifo_depth;
Doesn't that effectively revert 3288d5cb40c0 ? Why do you need to do so?
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} static int sun6i_spi_prepare_message(struct spi_master *master,@@ -255,8 +258,14 @@ static int sun6i_spi_transfer_one(struct spi_master *master, int ret = 0; u32 reg; - if (tfr->len > SUN6I_MAX_XFER_SIZE) - return -EINVAL; + /* A zero length transfer never finishes if programmed + in the hardware */
Improper comment style here. Please make sure to run checkpatch before sending your patches.
+ if (!tfr->len) + return 0;
Can that case even happen?
+ /* Don't support transfer larger than the FIFO */ + if (tfr->len > sspi->fifo_depth) + return -EMSGSIZE;
You're changing the return type, why?
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reinit_completion(&sspi->done); sspi->tx_buf = tfr->tx_buf;@@ -278,8 +287,7 @@ static int sun6i_spi_transfer_one(struct spi_master *master, */ trig_level = sspi->fifo_depth / 4 * 3; sun6i_spi_write(sspi, SUN6I_FIFO_CTL_REG, - (trig_level << SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_BITS) | - (trig_level << SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_BITS)); + (trig_level << SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_BITS)); reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);@@ -343,11 +351,8 @@ static int sun6i_spi_transfer_one(struct spi_master *master, sun6i_spi_fill_fifo(sspi, sspi->fifo_depth); /* Enable the interrupts */ - sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, SUN6I_INT_CTL_TC); sun6i_spi_enable_interrupt(sspi, SUN6I_INT_CTL_TC | SUN6I_INT_CTL_RF_RDY); - if (tx_len > sspi->fifo_depth) - sun6i_spi_enable_interrupt(sspi, SUN6I_INT_CTL_TF_ERQ);
This would also need to be explained in your commit log.
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/* Start the transfer */ reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);@@ -376,7 +381,9 @@ out: static irqreturn_t sun6i_spi_handler(int irq, void *dev_id) { struct sun6i_spi *sspi = dev_id; - u32 status = sun6i_spi_read(sspi, SUN6I_INT_STA_REG); + u32 status; + + status = sun6i_spi_read(sspi, SUN6I_INT_STA_REG);
Why is this change needed? Maxime -- Maxime Ripard, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 833 bytes Desc: not available URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20180404/f8e88e3c/attachment-0001.sig>