2022-12-26 15:09:01

by Ivan Bornyakov

Subject: [PATCH v2 0/3] Reliability improvements for Microchip MPF FPGA manager

A couple of reliability improvements for Microchip Polarfire FPGA
manager:
* move SPI I/O buffers out of stack
* rewrite status polling routine in a time measurable way

Also improve mpf_ops_write() code readability by separating single data
frame writing routine.

ChangeLog:
v1:
[https://lore.kernel.org/linux-fpga/[email protected]/]
v2:
* split into 3 distinct patches

Ivan Bornyakov (3):
fpga: microchip-spi: move SPI I/O buffers out of stack
fpga: microchip-spi: rewrite status polling in a time measurable way
fpga: microchip-spi: separate data frame write routine

drivers/fpga/microchip-spi.c | 138 ++++++++++++++++++-----------------
1 file changed, 73 insertions(+), 65 deletions(-)

--
2.38.2

2022-12-26 15:10:53

by Ivan Bornyakov

Subject: [PATCH v2 3/3] fpga: microchip-spi: separate data frame write routine

mpf_ops_write() function writes bitstream data to the FPGA by a smaller
frames. Introduce mpf_spi_frame_write() function which is for writing a
single data frame and use it in mpf_ops_write().

No functional changes intended.

Signed-off-by: Ivan Bornyakov <[email protected]>
---
drivers/fpga/microchip-spi.c | 36 +++++++++++++++++++++++-------------
1 file changed, 23 insertions(+), 13 deletions(-)

diff --git a/drivers/fpga/microchip-spi.c b/drivers/fpga/microchip-spi.c
index f3ddfab87499..f8a6872c865b 100644
--- a/drivers/fpga/microchip-spi.c
+++ b/drivers/fpga/microchip-spi.c
@@ -275,9 +275,30 @@ static int mpf_ops_write_init(struct fpga_manager *mgr,
return 0;
}

+static int mpf_spi_frame_write(struct mpf_priv *priv, const char *buf)
+{
+ struct spi_transfer xfers[2] = {
+ {
+ .tx_buf = &priv->tx,
+ .len = 1,
+ }, {
+ .tx_buf = buf,
+ .len = MPF_SPI_FRAME_SIZE,
+ },
+ };
+ int ret;
+
+ ret = mpf_poll_status(priv, 0);
+ if (ret < 0)
+ return ret;
+
+ priv->tx = MPF_SPI_FRAME;
+
+ return spi_sync_transfer(priv->spi, xfers, ARRAY_SIZE(xfers));
+}
+
static int mpf_ops_write(struct fpga_manager *mgr, const char *buf, size_t count)
{
- struct spi_transfer xfers[2] = { 0 };
struct mpf_priv *priv = mgr->priv;
struct device *dev = &mgr->dev;
int ret, i;
@@ -288,19 +309,8 @@ static int mpf_ops_write(struct fpga_manager *mgr, const char *buf, size_t count
return -EINVAL;
}

- xfers[0].tx_buf = &priv->tx;
- xfers[0].len = 1;
-
for (i = 0; i < count / MPF_SPI_FRAME_SIZE; i++) {
- xfers[1].tx_buf = buf + i * MPF_SPI_FRAME_SIZE;
- xfers[1].len = MPF_SPI_FRAME_SIZE;
-
- ret = mpf_poll_status(priv, 0);
- if (ret >= 0) {
- priv->tx = MPF_SPI_FRAME;
- ret = spi_sync_transfer(priv->spi, xfers, ARRAY_SIZE(xfers));
- }
-
+ ret = mpf_spi_frame_write(priv, buf + i * MPF_SPI_FRAME_SIZE);
if (ret) {
dev_err(dev, "Failed to write bitstream frame %d/%zu\n",
i, count / MPF_SPI_FRAME_SIZE);
--
2.38.2