On 6/11/20 1:46 AM, Luis Alberto Herrera wrote: > This change reverts aba3a882a178: "mtd: spi-nor: intel: provide a range > for poll_timout". That change introduces a performance regression when > reading sequentially from flash. Logging calls to intel_spi_read without > this change we get: > > Start MTD read > [ 20.045527] intel_spi_read(from=1800000, len=400000) > [ 20.045527] intel_spi_read(from=1800000, len=400000) > [ 282.199274] intel_spi_read(from=1c00000, len=400000) > [ 282.199274] intel_spi_read(from=1c00000, len=400000) > [ 544.351528] intel_spi_read(from=2000000, len=400000) > [ 544.351528] intel_spi_read(from=2000000, len=400000) > End MTD read > > With this change: > > Start MTD read > [ 21.942922] intel_spi_read(from=1c00000, len=400000) > [ 21.942922] intel_spi_read(from=1c00000, len=400000) > [ 23.784058] intel_spi_read(from=2000000, len=400000) > [ 23.784058] intel_spi_read(from=2000000, len=400000) > [ 25.625006] intel_spi_read(from=2400000, len=400000) > [ 25.625006] intel_spi_read(from=2400000, len=400000) > End MTD read > > Signed-off-by: Luis Alberto Herrera <luisalbe...@google.com> > --- > drivers/mtd/spi-nor/controllers/intel-spi.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/mtd/spi-nor/controllers/intel-spi.c > b/drivers/mtd/spi-nor/controllers/intel-spi.c > index 61d2a0ad2131..2b89361a0d3a 100644 > --- a/drivers/mtd/spi-nor/controllers/intel-spi.c > +++ b/drivers/mtd/spi-nor/controllers/intel-spi.c > @@ -292,7 +292,7 @@ static int intel_spi_wait_hw_busy(struct intel_spi *ispi) > u32 val; > > return readl_poll_timeout(ispi->base + HSFSTS_CTL, val, > - !(val & HSFSTS_CTL_SCIP), 40, > + !(val & HSFSTS_CTL_SCIP), 0,
Would 10 us keep the performance as it was before? Cheers, ta