diff options
| author | Feng Tang <feng.tang@intel.com> | 2010-12-24 13:59:09 +0800 |
|---|---|---|
| committer | Grant Likely <grant.likely@secretlab.ca> | 2010-12-24 01:08:42 -0700 |
| commit | ebf45b7d029eb065819bfede8b30455630d76c68 (patch) | |
| tree | f42bcb8575af3477b1d9293bed7de3f21734236f /drivers/spi/dw_spi.c | |
| parent | 5e8b821de333f472d33e3052a8dd1c43bf3ce433 (diff) | |
| download | lwn-ebf45b7d029eb065819bfede8b30455630d76c68.tar.gz lwn-ebf45b7d029eb065819bfede8b30455630d76c68.zip | |
spi/dw_spi: Fix too short timeout in spi polling loop
The SPI polling loop timeout only works with HZ=100 as the loop was
actually too short.
Also add appropriate cpu_relax() in the busy wait loops...
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'drivers/spi/dw_spi.c')
| -rw-r--r-- | drivers/spi/dw_spi.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c index 0838c79861e4..25238a82e45e 100644 --- a/drivers/spi/dw_spi.c +++ b/drivers/spi/dw_spi.c @@ -164,20 +164,23 @@ static inline void mrst_spi_debugfs_remove(struct dw_spi *dws) static void wait_till_not_busy(struct dw_spi *dws) { - unsigned long end = jiffies + 1 + usecs_to_jiffies(1000); + unsigned long end = jiffies + 1 + usecs_to_jiffies(5000); while (time_before(jiffies, end)) { if (!(dw_readw(dws, sr) & SR_BUSY)) return; + cpu_relax(); } dev_err(&dws->master->dev, - "DW SPI: Status keeps busy for 1000us after a read/write!\n"); + "DW SPI: Status keeps busy for 5000us after a read/write!\n"); } static void flush(struct dw_spi *dws) { - while (dw_readw(dws, sr) & SR_RF_NOT_EMPT) + while (dw_readw(dws, sr) & SR_RF_NOT_EMPT) { dw_readw(dws, dr); + cpu_relax(); + } wait_till_not_busy(dws); } |