@@ -427,6 +427,7 @@ static inline void enable_cs(struct s3c64xx_spi_driver_data *sdd,
static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd,
struct spi_transfer *xfer, int dma_mode)
{
+ struct device *dev = &sdd->pdev->dev;
void __iomem *regs = sdd->regs;
unsigned long val;
int ms;
@@ -439,16 +440,21 @@ static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd,
val = msecs_to_jiffies(ms) + 10;
val = wait_for_completion_timeout(&sdd->xfer_completion, val);
} else {
+ ulong deadline;
u32 status;
- val = msecs_to_loops(ms);
+
+ deadline = jiffies + msecs_to_jiffies(ms);
do {
status = readl(regs + S3C64XX_SPI_STATUS);
- } while (RX_FIFO_LVL(status, sdd) < xfer->len && --val);
+ if (time_after(jiffies, deadline)) {
+ dev_warn(dev, "RX timeout level=%d, need=%d\n",
+ RX_FIFO_LVL(status, sdd), xfer->len);
+ return -EIO;
+ }
+ cpu_relax();
+ } while (RX_FIFO_LVL(status, sdd) < xfer->len);
}
- if (!val)
- return -EIO;
-
if (dma_mode) {
u32 status;
@@ -460,17 +466,18 @@ static int wait_for_xfer(struct s3c64xx_spi_driver_data *sdd,
* Xfer involved Rx(with or without Tx).
*/
if (xfer->rx_buf == NULL) {
- val = msecs_to_loops(10);
- status = readl(regs + S3C64XX_SPI_STATUS);
- while ((TX_FIFO_LVL(status, sdd)
- || !S3C64XX_SPI_ST_TX_DONE(status, sdd))
- && --val) {
- cpu_relax();
- status = readl(regs + S3C64XX_SPI_STATUS);
- }
+ ulong deadline;
- if (!val)
- return -EIO;
+ deadline = jiffies + msecs_to_jiffies(10);
+ do {
+ status = readl(regs + S3C64XX_SPI_STATUS);
+ if (time_after(jiffies, deadline)) {
+ dev_warn(dev, "TX timeout level=%d\n",
+ TX_FIFO_LVL(status, sdd));
+ return -EIO;
+ }
+ } while (TX_FIFO_LVL(status, sdd) ||
+ !S3C64XX_SPI_ST_TX_DONE(status, sdd));
}
} else {
/* If it was only Tx */
The current timeout uses loops, but does not actually use an empty loop. In fact it checks SPI registers which are pretty slow to read. As a result the timeout ends up being several seconds most of the time. Change this to use jiffies instead. Signed-off-by: Simon Glass <sjg@chromium.org> --- drivers/spi/spi-s3c64xx.c | 37 ++++++++++++++++++++++--------------- 1 files changed, 22 insertions(+), 15 deletions(-)