linux_dsm_epyc7002/drivers
Ville Syrjälä c2b6337446 drm/i915: Enable DPLL VGA mode before P1/P2 divider write
Apparently writing the DPLL register P1/P2 divider fields won't trigger
an actual change in the DPLL output unless VGA mode is enabled for
prior to the register write that changes the P1/P2 dividers. The write
with the new P1/P2 divider can itself disable VGA mode again without
problems.

I tested the behaviour on my 946GZ, and when manually frobbing the
register with the display on, the behaviour is very clear. However I
can't explain why this machine actually works. The P1/P2 divider
changes caused by normal modesets do seem to make it through to the
hardware somehow since I get a stable picture on the monitor with
any resolution. Maybe it's the "three times for luck" stuff that
somehow masks the problem, or something.

But apparently there are machines (eg. Nick Bowler's G45) where that
isn't the case and we fail to get the correct clock from the DPLL.

Things used to work because we enabled VGA mode for disabled DPLLs,
so when re-enabling the DPLL VGA mode was enabled just prior to the
first register write, and hence the P1/P2 change went through without
a hitch. That got changed in

b8afb9113c drm/i915: Keep GMCH DPLL VGA mode always disabled

in the name of consistency. In order to keep the consistency part,
leave VGA mode disabled for disabled DPLLs, but turn it on just prior
to updating the P1/P2 dividers to make sure the hardware picks up
on the new values.

Cc: Nick Bowler <nbowler@draconx.ca>
Reported-by: Nick Bowler <nbowler@draconx.ca>
Tested-by: Nick Bowler <nbowler@draconx.ca>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2015-10-13 17:03:38 +03:00
..
accessibility
acpi Merge branch 'acpi-ec' 2015-10-01 22:30:35 +02:00
amba
android mm: mark most vm_operations_struct const 2015-09-10 13:29:01 -07:00
ata Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2015-09-03 16:55:55 -07:00
atm solos-pci: Increase headroom on received packets 2015-09-17 21:29:07 -07:00
auxdisplay
base regmap: Fixes for v4.3 2015-10-07 14:15:49 +01:00
bcma
block blk-mq: fix racy updates of rq->errors 2015-10-01 10:10:55 +02:00
bluetooth Bluetooth: hci_bcm: Fix crash on suspend 2015-08-28 21:09:14 +02:00
bus arm-cci500: Don't enable PMU driver by default 2015-09-28 16:31:17 -07:00
cdrom
char Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2015-09-26 21:05:23 -04:00
clk Merge branch 'for-4.3-rc/ti-clk-fixes' of https://github.com/t-kristo/linux-pm into clk-fixes 2015-10-02 11:22:23 -07:00
clocksource clocksource/drivers/keystone: Fix bad NO_IRQ usage 2015-09-29 14:33:51 +02:00
connector
cpufreq cpufreq: prevent lockup on reading scaling_available_frequencies 2015-10-08 21:47:56 +02:00
cpuidle Additional power management and ACPI material for v4.3-rc1 2015-09-11 19:11:06 -07:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2015-09-26 21:05:23 -04:00
dca
devfreq PM / devfreq: fix double kfree 2015-10-02 11:05:58 +09:00
dio
dma dmaengine fixes for 4.3-rc4 2015-10-02 14:46:15 -04:00
dma-buf
edac edac updates for v4.3-rc1 2015-09-11 16:21:12 -07:00
eisa
extcon extcon: Fix attached value returned by is_extcon_changed 2015-09-21 15:07:19 +09:00
firewire
firmware arm64/efi: Fix boot crash by not padding between EFI_MEMORY_RUNTIME regions 2015-10-01 12:51:28 +02:00
fmc
gpio Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-09-18 08:11:42 -07:00
gpu drm/i915: Enable DPLL VGA mode before P1/P2 divider write 2015-10-13 17:03:38 +03:00
hid Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2015-09-04 12:02:11 -07:00
hsi mm: mark most vm_operations_struct const 2015-09-10 13:29:01 -07:00
hv Drivers: hv: vmbus: fix init_vp_index() for reloading hv_netvsc 2015-09-20 22:44:51 -07:00
hwmon hwmon: (pwm-fan) Fix module autoload for OF platform driver 2015-09-20 17:50:19 -07:00
hwspinlock
hwtracing/coresight
i2c Merge branch 'i2c/for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2015-09-08 16:16:26 -07:00
ide
idle intel_idle: Skylake Client Support - updated 2015-09-10 14:03:44 -04:00
iio This is the bulk of GPIO changes for the v4.3 kernel cycle: 2015-09-04 10:07:45 -07:00
infiniband Changes for 4.3-rc4 2015-10-01 16:38:52 -04:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2015-10-02 17:53:25 -04:00
iommu Merge git://git.infradead.org/intel-iommu 2015-10-02 07:59:29 -04:00
ipack
irqchip Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-10-04 11:40:09 +01:00
isdn libnvdimm for 4.3: 2015-09-08 14:35:59 -07:00
leds leds:lp55xx: Correct Kconfig dependency for f/w user helper 2015-09-17 10:02:20 +02:00
lguest
macintosh powerpc updates for 4.3 2015-09-03 16:41:38 -07:00
mailbox Merge branch 'mailbox-for-next' of git://git.linaro.org/landing-teams/working/fujitsu/integration 2015-09-05 18:11:04 -07:00
mcb mcb: Fix error handling in mcb_pci_probe() 2015-10-05 05:10:01 +01:00
md One bug fix for raid1/raid10. 2015-10-11 09:35:51 -07:00
media media updates for v4.3-rc1 2015-09-11 16:42:39 -07:00
memory IOMMU Updates for Linux v4.3 2015-09-08 17:22:35 -07:00
memstick
message
mfd genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
misc mei: hbm: fix error in state check logic 2015-10-04 12:19:23 +01:00
mmc mmc: sdhci-of-at91: use SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST quirk 2015-10-08 19:55:05 +02:00
mtd A few MTD fixes: 2015-10-07 09:35:15 +01:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-10-01 21:55:35 -04:00
nfc This is the bulk of GPIO changes for the v4.3 kernel cycle: 2015-09-04 10:07:45 -07:00
ntb NTB: Fix range check on memory window index 2015-09-07 15:27:12 -04:00
nubus
nvdimm pmem: add proper fencing to pmem_rw_page() 2015-09-17 11:49:28 -04:00
nvmem nvmem: sunxi: Check for memory allocation failure 2015-10-04 12:09:43 +01:00
of Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-09-26 06:01:33 -04:00
oprofile
parisc PCI: Revert "PCI: Call pci_read_bridge_bases() from core instead of arch code" 2015-09-15 13:18:04 -05:00
parport
pci Merge branches 'pm-pci' and 'acpi-pci' 2015-10-01 22:30:12 +02:00
pcmcia pcmcia: soc_common: remove skt_dev_info's clk pointer 2015-09-03 16:01:03 +01:00
perf
phy phy: berlin-sata: Fix module autoload for OF platform driver 2015-09-25 17:01:14 +05:30
pinctrl Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-09-18 08:11:42 -07:00
platform platform-drivers-x86 for 4.3-2 2015-09-17 21:41:02 -07:00
pnp
power power supply and reset fixes for the v4.3 series 2015-09-17 12:25:42 -07:00
powercap powercap / RAPL: disable the 2nd power limit properly 2015-08-29 01:46:40 +02:00
pps
ps3
ptp
pwm pwm: Changes for v4.3-rc1 2015-09-09 10:55:32 -07:00
rapidio
ras
regulator Merge remote-tracking branch 'regulator/fix/axp20x' into regulator-linus 2015-10-06 12:00:42 +01:00
remoteproc
reset reset: ath79: Fix missing spin_lock_init 2015-09-01 14:48:40 +02:00
rpmsg
rtc rtc: abx80x: fix RTC write bit 2015-09-05 19:37:31 +02:00
s390 virtio: fixes on top of 4.3-rc1 2015-09-18 09:28:20 -07:00
sbus
scsi SCSI fixes on 20151010 2015-10-11 10:02:30 -07:00
sfi
sh SH Drivers Updates for v4.3 2015-09-21 12:02:27 -07:00
sn
soc genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
spi Merge remote-tracking branches 'spi/fix/davinci' and 'spi/fix/sh-msiof' into spi-linus 2015-10-07 11:43:39 +01:00
spmi genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
ssb
staging staging: speakup: fix speakup-r regression 2015-10-04 19:57:20 +01:00
target iscsi-target: Avoid OFMarker + IFMarker negotiation 2015-09-24 23:24:46 -07:00
tc
thermal thermal: avoid division by zero in power allocator 2015-10-01 21:42:35 -04:00
thunderbolt thunderbolt: Allow loading of module on recent Apple MacBooks with thunderbolt 2 controller 2015-09-20 15:20:11 -07:00
tty drivers/tty: require read access for controlling terminal 2015-10-04 19:20:30 +01:00
uio
usb usb: Add device quirk for Logitech PTZ cameras 2015-10-04 11:01:13 +01:00
uwb
vfio
vhost virtio: fixes on top of 4.3-rc1 2015-09-18 09:28:20 -07:00
video video: of: fix memory leak 2015-10-07 14:13:59 +03:00
virt
virtio virtio_balloon: do not change memory amount visible via /proc/meminfo 2015-09-08 13:32:11 +03:00
vlynq
vme
w1 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2015-09-01 18:46:42 -07:00
watchdog watchdog: iTCO: Fix dependencies on I2C 2015-09-28 10:56:10 +02:00
xen Merge branch 'akpm' (patches from Andrew) 2015-09-10 18:19:42 -07:00
zorro
Kconfig Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm 2015-09-03 16:27:01 -07:00
Makefile This is the bulk of pin control changes for the v4.3 development 2015-09-04 10:22:09 -07:00