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Aswath Govindraju 7b1d968133
spi: omap2-mcspi: Improve performance waiting for CHSTAT 
This reverts commit 13d515c796 (spi: omap2-mcspi: Switch to
readl_poll_timeout()).

The amount of time spent polling for the MCSPI_CHSTAT bits to be set on
AM335x-icev2 platform is less than 1us (about 0.6us) in most cases, with
or without using DMA. So, in most cases the function need not sleep.
Also, setting the sleep_usecs to zero would not be optimal here because
ktime_add_us() used in readl_poll_timeout() is slower compared to the
direct addition used after the revert. So, it is sub-optimal to use
readl_poll_timeout in this case.

When DMA is not enabled, this revert results in an increase of about 27%
in throughput and decrease of about 20% in CPU usage. However, the CPU
usage and throughput are almost the same when used with DMA.

Therefore, fix this by reverting the commit which switched to using
readl_poll_timeout().

Fixes: 13d515c796 ("spi: omap2-mcspi: Switch to readl_poll_timeout()")
Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
Link: https://lore.kernel.org/r/20200910122624.8769-1-a-govindraju@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>
 		2020-09-22 01:04:20 +01:00
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accessibility Char/Misc driver fixes for 5.9-rc3 2020-08-26 10:50:50 -07:00
acpi Merge branch 'acpi-mm' 2020-08-28 21:17:56 +02:00
amba
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android
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ata libata-5.9-2020-09-04 2020-09-04 13:19:19 -07:00
atm Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-09-03 18:50:48 -07:00
auxdisplay A trivial patch for auxdisplay: 2020-09-05 14:22:46 -07:00
base Device properties framework fix for 5.9-rc3 2020-08-28 13:23:31 -07:00
bcma
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block block-5.9-2020-08-28 2020-08-28 16:38:29 -07:00
bluetooth
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bus treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
cdrom
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char Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2020-08-30 15:53:44 -07:00
clk More ACPI updates for 5.9-rc1 2020-08-15 08:18:22 -07:00
clocksource treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
connector
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counter
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cpufreq cpufreq: intel_pstate: Fix intel_pstate_get_hwp_max() for turbo disabled 2020-09-01 21:15:00 +02:00
cpuidle cpuidle: Make CPUIDLE_FLAG_TLB_FLUSHED generic 2020-08-26 12:41:53 +02:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2020-08-30 15:53:44 -07:00
dax xen: branch for v5.9-rc4 2020-09-06 09:59:27 -07:00
dca
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devfreq
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dio
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dma dmaengine fixes for v5.9-rc4 2020-09-04 12:12:39 -07:00
dma-buf A set of locking fixes and updates: 2020-08-10 19:07:44 -07:00
edac A fix to properly clear ghes_edac driver state on driver remove so that 2020-08-30 10:47:23 -07:00
eisa
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extcon
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firewire treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
firmware A set of fixes for interrupt chip drivers: 2020-08-30 11:56:54 -07:00
fpga
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fsi
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gnss
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gpio treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
gpu xen: branch for v5.9-rc4 2020-09-06 09:59:27 -07:00
greybus
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hid Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid 2020-09-02 12:55:46 -07:00
hsi treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
hv hyperv-fixes for 5.9-rc3 2020-08-26 10:44:15 -07:00
hwmon hwmon fixes for v5.9-rc3 2020-08-29 12:37:00 -07:00
hwspinlock
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hwtracing treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
i2c Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2020-08-29 13:13:44 -07:00
i3c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
ide treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
idle cpuidle: Make CPUIDLE_FLAG_TLB_FLUSHED generic 2020-08-26 12:41:53 +02:00
iio iio: dpot-dac: fix code comment in dpot_dac_read_raw() 2020-08-26 14:02:24 -05:00
infiniband treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
input treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
interconnect Char/Misc driver patches for 5.9-rc1 2020-08-05 11:43:47 -07:00
iommu iommu/vt-d: Handle 36bit addressing for x86-32 2020-09-04 12:14:28 +02:00
ipack
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irqchip A set of fixes for interrupt chip drivers: 2020-08-30 11:56:54 -07:00
isdn treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
leds LEDs changes for 5.9-rc1. 2020-08-05 19:24:27 -07:00
lightnvm treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
macintosh treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
mailbox iomap: constify ioreadX() iomem argument (as in generic implementation) 2020-08-14 19:56:57 -07:00
mcb
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md dm thin metadata: Fix use-after-free in dm_bm_set_read_only 2020-09-02 13:38:40 -04:00
media media fixes for v5.9-rc4 2020-09-03 08:22:16 -07:00
memory treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
memstick treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
message treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
mfd - Bug Fixes 2020-08-28 10:15:33 -07:00
misc Char/Misc driver fixes for 5.9-rc3 2020-08-26 10:50:50 -07:00
mmc MMC host: 2020-08-31 11:22:57 -07:00
most
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mtd This pull request contains changes for JFFS2, UBI and UBIFS 2020-08-10 18:20:04 -07:00
mux treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-09-03 18:50:48 -07:00
nfc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-09-03 18:50:48 -07:00
ntb treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
nubus
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nvdimm libnvdimm: KASAN: global-out-of-bounds Read in internal_create_group 2020-08-17 14:47:38 -06:00
nvme block-5.9-2020-09-04 2020-09-04 13:04:51 -07:00
nvmem
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of of: address: Work around missing device_type property in pcie nodes 2020-08-19 16:30:57 -06:00
opp Merge branch 'opp/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm 2020-09-01 19:44:20 +02:00
oprofile
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parisc Merge branch 'parisc-5.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2020-08-12 12:41:15 -07:00
parport treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
pci treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
pcmcia treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
perf treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
phy treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
pinctrl This is the bulk of the pin control changes for the v5.9 2020-08-09 12:52:28 -07:00
platform treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
pnp
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power treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
powercap This tree adds the sched_set_fifo*() encapsulation APIs to remove 2020-08-06 11:55:43 -07:00
pps
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ps3 treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
ptp ptp: ptp_clockmatrix: use i2c_master_send for i2c write 2020-08-19 16:23:22 -07:00
pwm pwm: Changes for v5.9-rc1 2020-08-14 16:00:09 -07:00
rapidio treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
ras
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regulator treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
remoteproc treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
reset treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
rpmsg treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
rtc treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
s390 treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
sbus
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scsi SCSI fixes on 20200901 2020-09-01 14:12:44 -07:00
sfi
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sh iomap: constify ioreadX() iomem argument (as in generic implementation) 2020-08-14 19:56:57 -07:00
siox
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slimbus
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soc treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
soundwire
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spi spi: omap2-mcspi: Improve performance waiting for CHSTAT 2020-09-22 01:04:20 +01:00
spmi
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ssb treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
staging media fixes for v5.9-rc4 2020-09-03 08:22:16 -07:00
target treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
tc
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tee
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thermal - Fix bogus thermal shutdowns for omap4430 where bogus values 2020-09-04 12:49:03 -07:00
thunderbolt treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
tty TTY/Serial fixes for 5.9-rc3 2020-08-26 10:58:20 -07:00
uio
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usb USB fixes for 5.9-rc3 - take 2 2020-08-30 10:51:03 -07:00
vdpa vdpa/mlx5: Avoid warnings about shifts on 32-bit platforms 2020-08-26 08:13:59 -04:00
vfio treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
vhost Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-09-03 18:50:48 -07:00
video powerpc fixes for 5.9 #4 2020-08-30 10:56:12 -07:00
virt
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virtio virtio: pci: constify ioreadX() iomem argument (as in generic implementation) 2020-08-14 19:56:57 -07:00
visorbus
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vlynq
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vme
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w1
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watchdog treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
xen xen: branch for v5.9-rc4 2020-09-06 09:59:27 -07:00
zorro
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Kconfig
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Makefile
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