Re: [PATCH 1/9] spi: sunxi: fix transfer timeout
From: Maxime Ripard <hidden>
Date: 2015-08-20 14:43:15
Also in:
linux-arm-kernel, linux-spi, lkml
On Thu, Aug 20, 2015 at 02:19:45PM -0000, Michal Suchanek wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- drivers/spi/spi-sun4i.c | 10 +++++++++- drivers/spi/spi-sun6i.c | 10 +++++++++- 2 files changed, 18 insertions(+), 2 deletions(-)diff --git a/drivers/spi/spi-sun4i.c b/drivers/spi/spi-sun4i.c index fbb0a4d..48532ec 100644 --- a/drivers/spi/spi-sun4i.c +++ b/drivers/spi/spi-sun4i.c@@ -170,6 +170,7 @@ static int sun4i_spi_transfer_one(struct spi_master *master, { 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 spi_master *master, reg = sun4i_spi_read(sspi, SUN4I_CTL_REG); sun4i_spi_write(sspi, SUN4I_CTL_REG, reg | SUN4I_CTL_XCH); + tx_time = max_t(int, tfr->len * 8 * 2 / (speed / 1000), 100); + 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, speed, + jiffies_to_msecs(end - start), tx_time);
Timeout already contains the number of jiffies elapsed (and I'm not sure anyone reading that message would get that the last number is actually the maximum timeout). Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com