On 04/04/2018 09:50 AM, Maxime Ripard wrote:
On Tue, Apr 03, 2018 at 06:44:46PM +0300, Sergey Suloev wrote:
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 <ssuloev@xxxxxxxxxxxxx>
---
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?
Need what?
Change is supposed to restrict max transfer size for PIO mode otherwise
it will fail.
The maximum transfer length = FIFO depth for PIO mode.
}
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.
ok
+ if (!tfr->len)
+ return 0;
Can that case even happen?
Not sure, just for safety.
+ /* Don't support transfer larger than the FIFO */
+ if (tfr->len > sspi->fifo_depth)
+ return -EMSGSIZE;
You're changing the return type, why?
As a more appropriate one
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.
What exactly and in what way ?
/* 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?
A minor one, for readability.
Maxime
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