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authorRafał Miłecki <rafal@milecki.pl>2018-10-11 09:42:17 +0200
committerMark Brown <broonie@kernel.org>2018-10-11 15:00:34 +0100
commit940ec770c295682993d1cccce3081fd7c74fece8 (patch)
tree6114fddda9d30a6542e7d39693103c113eb55b4e /drivers/spi
parent0976eda7915507fe94e07870c19d717c9994b57a (diff)
downloadlinux-940ec770c295682993d1cccce3081fd7c74fece8.tar.bz2
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
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi-bcm-qspi.c2
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