Messages in this thread | | | Subject | Re: [PATCH] mtd: revert "spi-nor: intel: provide a range for poll_timout" | From | Alexander Sverdlin <> | Date | Thu, 23 Jul 2020 11:05:41 +0200 |
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Hello Tudor,
On 22/07/2020 19:03, Tudor.Ambarus@microchip.com wrote: > On 7/22/20 7:37 PM, Alexander Sverdlin wrote:
[...]
>> I've performed my testing as well and got the following results: >> >> Vanilla Linux 4.9 (i.e. before the introduction of the offending >> patch): >> >> dd if=/dev/flash/by-name/XXX of=/dev/null bs=4k >> 1280+0 records in >> 1280+0 records out >> 5242880 bytes (5.2 MB, 5.0 MiB) copied, 3.91981 s, 1.3 MB/s >> >> Vanilla 4.19 (i.e. with offending patch): >> >> dd if=/dev/flash/by-name/XXX of=/dev/null bs=4k >> 1280+0 records in >> 1280+0 records out >> 5242880 bytes (5.2 MB, 5.0 MiB) copied, 6.70891 s, 781 kB/s >> >> 4.19 + revert: >> >> dd if=/dev/flash/by-name/XXX of=/dev/null bs=4k >> 1280+0 records in >> 1280+0 records out >> 5242880 bytes (5.2 MB, 5.0 MiB) copied, 3.90503 s, 1.3 MB/s >> >> Therefore it looks good from my PoV: >> >> Tested-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
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> would you put 10 us here >>> INTEL_SPI_TIMEOUT * 1000); >>> } >>> >>> @@ -301,7 +301,7 @@ static int intel_spi_wait_sw_busy(struct intel_spi *ispi) >>> u32 val; >>> >>> return readl_poll_timeout(ispi->sregs + SSFSTS_CTL, val, >>> - !(val & SSFSTS_CTL_SCIP), 40, >>> + !(val & SSFSTS_CTL_SCIP), 0, > > also here, and re-do a test? I'm curios if the performance will be > as it was before.
with 10us it looks like this:
dd if=/dev/flash/by-name/... of=/dev/null bs=4k 1280+0 records in 1280+0 records out 5242880 bytes (5.2 MB, 5.0 MiB) copied, 4.33816 s, 1.2 MB/s
Which means, there is a performance regression and it would depend on the test case, how bad it will be...
-- Best regards, Alexander Sverdlin.
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