[PATCH 4.4 42/68] spi: sunxi: fix transfer timeout

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Michal Suchanek <hramr...@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 <hramr...@gmail.com>
Acked-by: Maxime Ripard <maxime.rip...@free-electrons.com>
Signed-off-by: Mark Brown <broo...@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 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;
@@ -279,9 +280,16 @@ 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;
        }