d4b8d51580
As usual, this patches were taken (and rebased) from https://github.com/raspberrypi/linux/commits/rpi-4.1.y Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com> SVN-Revision: 47922
53 lines
1.8 KiB
Diff
53 lines
1.8 KiB
Diff
From 3604c2a5b623829c9127d312813f3427531ebfcd Mon Sep 17 00:00:00 2001
|
|
From: Martin Sperl <kernel@martin.sperl.org>
|
|
Date: Wed, 29 Jul 2015 07:34:10 +0000
|
|
Subject: [PATCH 176/222] spi: bcm2835: fix overflow in calculation of transfer
|
|
time
|
|
|
|
This resulted in the use of polling mode when other approaches
|
|
(dma or interrupts) would have been more appropriate.
|
|
|
|
Happened for transfers longer than 477 bytes.
|
|
|
|
Reported-by: Noralf Tronnes <noralf@tronnes.org>
|
|
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
|
|
Signed-off-by: Mark Brown <broonie@kernel.org>
|
|
(cherry picked from commit 0122a5183088e3117bb9c8fbe248914efb502f3f)
|
|
---
|
|
drivers/spi/spi-bcm2835.c | 10 ++++++----
|
|
1 file changed, 6 insertions(+), 4 deletions(-)
|
|
|
|
--- a/drivers/spi/spi-bcm2835.c
|
|
+++ b/drivers/spi/spi-bcm2835.c
|
|
@@ -480,7 +480,7 @@ static int bcm2835_spi_transfer_one_poll
|
|
struct spi_device *spi,
|
|
struct spi_transfer *tfr,
|
|
u32 cs,
|
|
- unsigned long xfer_time_us)
|
|
+ unsigned long long xfer_time_us)
|
|
{
|
|
struct bcm2835_spi *bs = spi_master_get_devdata(master);
|
|
unsigned long timeout;
|
|
@@ -531,7 +531,8 @@ static int bcm2835_spi_transfer_one(stru
|
|
{
|
|
struct bcm2835_spi *bs = spi_master_get_devdata(master);
|
|
unsigned long spi_hz, clk_hz, cdiv;
|
|
- unsigned long spi_used_hz, xfer_time_us;
|
|
+ unsigned long spi_used_hz;
|
|
+ unsigned long long xfer_time_us;
|
|
u32 cs = bcm2835_rd(bs, BCM2835_SPI_CS);
|
|
|
|
/* set clock */
|
|
@@ -573,9 +574,10 @@ static int bcm2835_spi_transfer_one(stru
|
|
bs->rx_len = tfr->len;
|
|
|
|
/* calculate the estimated time in us the transfer runs */
|
|
- xfer_time_us = tfr->len
|
|
+ xfer_time_us = (unsigned long long)tfr->len
|
|
* 9 /* clocks/byte - SPI-HW waits 1 clock after each byte */
|
|
- * 1000000 / spi_used_hz;
|
|
+ * 1000000;
|
|
+ do_div(xfer_time_us, spi_used_hz);
|
|
|
|
/* for short requests run polling*/
|
|
if (xfer_time_us <= BCM2835_SPI_POLLING_LIMIT_US)
|