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author | 2022-11-03 09:00:42 +0100 | |
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committer | 2022-11-03 13:25:40 +0000 | |
commit | 62aa1a344b0904549f6de7af958e8a1136fd5228 (patch) | |
tree | a68c074add5c022530abbe55e1dbc322303dfeb0 /tools/perf/scripts/python/call-graph-from-sql.py | |
parent | spi: meson-spicc: fix do_div build error on non-arm64 (diff) | |
download | linux-dev-62aa1a344b0904549f6de7af958e8a1136fd5228.tar.xz linux-dev-62aa1a344b0904549f6de7af958e8a1136fd5228.zip |
spi: stm32: fix stm32_spi_prepare_mbr() that halves spi clk for every run
When this driver is used with a driver that uses preallocated spi_transfer
structs. The speed_hz is halved by every run. This results in:
spi_stm32 44004000.spi: SPI transfer setup failed
ads7846 spi0.0: SPI transfer failed: -22
Example when running with DIV_ROUND_UP():
- First run; speed_hz = 1000000, spi->clk_rate 125000000
div 125 -> mbrdiv = 7, cur_speed = 976562
- Second run; speed_hz = 976562
div 128,00007 (roundup to 129) -> mbrdiv = 8, cur_speed = 488281
- Third run; speed_hz = 488281
div 256,000131072067109 (roundup to 257) and then -EINVAL is returned.
Use DIV_ROUND_CLOSEST to allow to round down and allow us to keep the
set speed.
Signed-off-by: Sean Nyekjaer <sean@geanix.com>
Link: https://lore.kernel.org/r/20221103080043.3033414-1-sean@geanix.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'tools/perf/scripts/python/call-graph-from-sql.py')
0 files changed, 0 insertions, 0 deletions