linux_dsm_epyc7002/arch/arm
Robert Jarzmik 9ba63e3cc8 ARM: pxa: pxa_cplds: fix interrupt handling
Since its initial commit, the driver is buggy for multiple interrupts
handling. The translation from the former lubbock.c file was not
complete, and might stall all interrupt handling when multiple
interrupts occur.

This is especially true when inside the interrupt handler and if a new
interrupt comes and is not handled, leaving the output line still held,
and not creating a transition as the GPIO block behind would expect to
trigger another cplds_irq_handler() call.

For the record, the hardware is working as follows.

The interrupt mechanism relies on :
 - one status register
 - one mask register

Let's suppose the input irq lines are called :
 - i_sa1111
 - i_lan91x
 - i_mmc_cd
Let's suppose the status register for each irq line is called :
 - status_sa1111
 - status_lan91x
 - status_mmc_cd
Let's suppose the interrupt mask for each irq line is called :
 - irqen_sa1111
 - irqen_lan91x
 - irqen_mmc_cd
Let's suppose the output irq line, connected to GPIO0 is called :
 - o_gpio0

The behavior is as follows :
 - o_gpio0 = not((status_sa1111 & irqen_sa1111) |
		 (status_lan91x & irqen_lan91x) |
		 (status_mmc_cd & irqen_mmc_cd))
   => this is a N-to-1 NOR gate and multiple AND gates
 - irqen_* is exactly as programmed by a write to the FPGA
 - status_* behavior is governed by a bi-stable D flip-flop
   => on next FPGA clock :
     - if i_xxx is high, status_xxx becomes 1
     - if i_xxx is low, status_xxx remains as it is
     - if software sets status_xxx to 0, the D flip-flop is reset
       => status_xxx becomes 0
       => on next FPGA clock cycle, if i_xxx is high, status_xxx becomes
	  1 again

Fixes: fc9e38c0f4 ("ARM: pxa: lubbock: use new pxa_cplds driver")
Reported-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
2016-09-09 18:09:53 +02:00
..
boot ARM: keystone: dts: add psci command definition 2016-08-02 19:35:28 -04:00
common dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
configs arm: trizeps4_defconfig: disable IDE subsystem 2016-08-09 08:16:59 +02:00
crypto
firmware
include dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
kernel arm: jump label may reference text in __exit 2016-08-04 08:50:07 -04:00
kvm KVM/ARM Changes for v4.8 - Take 2 2016-08-04 13:59:56 +02:00
lib
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mach-at91 ARM: SoC platform updates for v4.8 2016-08-01 18:27:08 -04:00
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mach-berlin
mach-clps711x clocksource/drivers/clps_711x: fixup for "ARM: clps711x: 2016-08-01 21:25:20 -04:00
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mach-hisi ARM: hisi: consolidate the hisilicon machine entries 2016-07-07 09:37:59 +01:00
mach-imx ARM: SoC platform updates for v4.8 2016-08-01 18:27:08 -04:00
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mach-keystone ARM: SoC defconfig updates for v4.8 2016-08-01 18:30:44 -04:00
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mach-nspire DeviceTree update for 4.8: 2016-07-30 11:32:01 -07:00
mach-omap1 ARM: SoC platform updates for v4.8 2016-08-01 18:27:08 -04:00
mach-omap2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-08-03 07:26:11 -04:00
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mach-oxnas Merge ARCH_[WANT_OPTIONAL|REQUIRE]_GPIOLIB changes into next/soc 2016-07-06 18:00:32 +02:00
mach-picoxcell ARM: SoC cleanups for v4.8 2016-08-01 18:21:13 -04:00
mach-prima2 ARM: SoC cleanups for v4.8 2016-08-01 18:21:13 -04:00
mach-pxa ARM: pxa: pxa_cplds: fix interrupt handling 2016-09-09 18:09:53 +02:00
mach-qcom
mach-realview
mach-rockchip ARM: SoC cleanups for v4.8 2016-08-01 18:21:13 -04:00
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mach-s3c64xx ARM: SoC platform updates for v4.8 2016-08-01 18:27:08 -04:00
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mach-tango ARM: tango: add Suspend-to-RAM support 2016-07-07 16:09:30 +02:00
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mach-u300 ARM: SoC cleanups for v4.8 2016-08-01 18:21:13 -04:00
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mach-versatile
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mm dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
net
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oprofile
plat-iop ARM: iop: Fix indentation 2016-07-07 18:06:40 +02:00
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plat-pxa ARM: pxa: remove platform dma code 2016-08-09 08:16:58 +02:00
plat-samsung ARM: SoC platform updates for v4.8 2016-08-01 18:27:08 -04:00
plat-versatile
probes
tools
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vfp arm: Convert VFP hotplug notifiers to state machine 2016-07-15 10:40:22 +02:00
xen dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
Kconfig PCI changes for the v4.8 merge window: 2016-08-02 17:12:29 -04:00
Kconfig-nommu
Kconfig.debug Merge tag 'arm-soc/for-4.8/soc-part2' of http://github.com/Broadcom/stblinux into next/soc 2016-07-07 16:09:25 +02:00
Makefile ARM: SoC platform updates for v4.8 2016-08-01 18:27:08 -04:00