From 76ee0235be5a24b34a63961189c8bafa9bcf2da3 Mon Sep 17 00:00:00 2001 From: Martin Sperl Date: Thu, 16 Apr 2015 07:51:26 +0000 Subject: [PATCH] spi: bcm2835: change timeout of polling driver to 1s The way that the timeout code is written in the polling function the timeout does also trigger when interrupted or rescheduled while in the polling loop. This patch changes the timeout from effectively 20ms (=2 jiffies) to 1 second and removes the time that the transfer really takes out of the computation, as - per design - this is <30us and the jiffie resolution is 10ms so that does not make any difference what so ever. Signed-off-by: Martin Sperl Signed-off-by: Mark Brown --- drivers/spi/spi-bcm2835.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c index f63864a893c5..37875cf942f7 100644 --- a/drivers/spi/spi-bcm2835.c +++ b/drivers/spi/spi-bcm2835.c @@ -164,13 +164,12 @@ static int bcm2835_spi_transfer_one_poll(struct spi_master *master, unsigned long xfer_time_us) { struct bcm2835_spi *bs = spi_master_get_devdata(master); - unsigned long timeout = jiffies + - max(4 * xfer_time_us * HZ / 1000000, 2uL); + /* set timeout to 1 second of maximum polling */ + unsigned long timeout = jiffies + HZ; /* enable HW block without interrupts */ bcm2835_wr(bs, BCM2835_SPI_CS, cs | BCM2835_SPI_CS_TA); - /* set timeout to 4x the expected time, or 2 jiffies */ /* loop until finished the transfer */ while (bs->rx_len) { /* read from fifo as much as possible */