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| author | Rafał Miłecki <rafal@milecki.pl> | 2018-10-11 09:42:17 +0200 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2018-10-11 15:00:34 +0100 |
| commit | 940ec770c295682993d1cccce3081fd7c74fece8 (patch) | |
| tree | 6114fddda9d30a6542e7d39693103c113eb55b4e | |
| parent | 0976eda7915507fe94e07870c19d717c9994b57a (diff) | |
| download | linux-stable-940ec770c295682993d1cccce3081fd7c74fece8.tar.gz linux-stable-940ec770c295682993d1cccce3081fd7c74fece8.tar.bz2 linux-stable-940ec770c295682993d1cccce3081fd7c74fece8.zip | |
spi: bcm-qspi: switch back to reading flash using smaller chunks
Fixing/optimizing bcm_qspi_bspi_read() performance introduced two
changes:
1) It added a loop to read all requested data using multiple BSPI ops.
2) It bumped max size of a single BSPI block request from 256 to 512 B.
The later change resulted in occasional BSPI timeouts causing a
regression.
For some unknown reason hardware doesn't always handle reads as expected
when using 512 B chunks. In such cases it may happen that BSPI returns
amount of requested bytes without the last 1-3 ones. It provides the
remaining bytes later but doesn't raise an interrupt until another LR
start.
Switching back to 256 B reads fixes that problem and regression.
Fixes: 345309fa7c0c ("spi: bcm-qspi: Fix bcm_qspi_bspi_read() performance")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
| -rw-r--r-- | drivers/spi/spi-bcm-qspi.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/spi/spi-bcm-qspi.c b/drivers/spi/spi-bcm-qspi.c index eb3d67f01e8c..584bcb018a62 100644 --- a/drivers/spi/spi-bcm-qspi.c +++ b/drivers/spi/spi-bcm-qspi.c @@ -89,7 +89,7 @@ #define BSPI_BPP_MODE_SELECT_MASK BIT(8) #define BSPI_BPP_ADDR_SELECT_MASK BIT(16) -#define BSPI_READ_LENGTH 512 +#define BSPI_READ_LENGTH 256 /* MSPI register offsets */ #define MSPI_SPCR0_LSB 0x000 |