[PATCH 3.16 186/305] spi: sunxi: fix transfer timeout

Ben Hutchings
2016-08-14T10:59:25Z

From: Michal Suchanek <hramrach@gmail.com>

commit 719bd6542044efd9b338a53dba1bef45f40ca169 upstream.

The trasfer timeout is fixed at 1000 ms. Reading a 4Mbyte flash over
1MHz SPI bus takes way longer than that. Calculate the timeout from the
actual time the transfer is supposed to take and multiply by 2 for good
measure.

Signed-off-by: Michal Suchanek <hramrach@gmail.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/spi/spi-sun4i.c | 10 +++++++++-
drivers/spi/spi-sun6i.c | 10 +++++++++-
2 files changed, 18 insertions(+), 2 deletions(-)

--- a/drivers/spi/spi-sun4i.c
+++ b/drivers/spi/spi-sun4i.c
@@ -170,6 +170,7 @@ static int sun4i_spi_transfer_one(struct
{
struct sun4i_spi *sspi = spi_master_get_devdata(master);
unsigned int mclk_rate, div, timeout;
+ unsigned int start, end, tx_time;
unsigned int tx_len = 0;
int ret = 0;
u32 reg;
@@ -286,9 +287,16 @@ static int sun4i_spi_transfer_one(struct
reg = sun4i_spi_read(sspi, SUN4I_CTL_REG);
sun4i_spi_write(sspi, SUN4I_CTL_REG, reg | SUN4I_CTL_XCH);

+ tx_time = max(tfr->len * 8 * 2 / (tfr->speed_hz / 1000), 100U);
+ start = jiffies;
timeout = wait_for_completion_timeout(&sspi->done,
- msecs_to_jiffies(1000));
+ msecs_to_jiffies(tx_time));
+ end = jiffies;
if (!timeout) {
+ dev_warn(&master->dev,
+ "%s: timeout transferring %u bytes@%iHz for %i(%i)ms",
+ dev_name(&spi->dev), tfr->len, tfr->speed_hz,
+ jiffies_to_msecs(end - start), tx_time);
ret = -ETIMEDOUT;
goto out;
}
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -160,6 +160,7 @@ static int sun6i_spi_transfer_one(struct
{
struct sun6i_spi *sspi = spi_master_get_devdata(master);
unsigned int mclk_rate, div, timeout;
+ unsigned int start, end, tx_time;
unsigned int tx_len = 0;
int ret = 0;
u32 reg;
@@ -269,9 +270,16 @@ static int sun6i_spi_transfer_one(struct
reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg | SUN6I_TFR_CTL_XCH);

+ tx_time = max(tfr->len * 8 * 2 / (tfr->speed_hz / 1000), 100U);
+ start = jiffies;
timeout = wait_for_completion_timeout(&sspi->done,
- msecs_to_jiffies(1000));
+ msecs_to_jiffies(tx_time));
+ end = jiffies;
if (!timeout) {
+ dev_warn(&master->dev,
+ "%s: timeout transferring %u bytes@%iHz for %i(%i)ms",
+ dev_name(&spi->dev), tfr->len, tfr->speed_hz,
+ jiffies_to_msecs(end - start), tx_time);
ret = -ETIMEDOUT;
goto out;
}