linux_old1/drivers
Manasi Navare 40ee6fbef7 drm: Add a new connector atomic property for link status
At the time userspace does setcrtc, we've already promised the mode
would work. The promise is based on the theoretical capabilities of
the link, but it's possible we can't reach this in practice. The DP
spec describes how the link should be reduced, but we can't reduce
the link below the requirements of the mode. Black screen follows.

One idea would be to have setcrtc return a failure. However, it
already should not fail as the atomic checks have passed. It would
also conflict with the idea of making setcrtc asynchronous in the
future, returning before the actual mode setting and link training.

Another idea is to train the link "upfront" at hotplug time, before
pruning the mode list, so that we can do the pruning based on
practical not theoretical capabilities. However, the changes for link
training are pretty drastic, all for the sake of error handling and
DP compliance, when the most common happy day scenario is the current
approach of link training at mode setting time, using the optimal
parameters for the mode. It is also not certain all hardware could do
this without the pipe on; not even all our hardware can do this. Some
of this can be solved, but not trivially.

Both of the above ideas also fail to address link degradation *during*
operation.

The solution is to add a new "link-status" connector property in order
to address link training failure in a way that:
a) changes the current happy day scenario as little as possible, to
avoid regressions, b) can be implemented the same way by all drm
drivers, c) is still opt-in for the drivers and userspace, and opting
out doesn't regress the user experience, d) doesn't prevent drivers
from implementing better or alternate approaches, possibly without
userspace involvement. And, of course, handles all the issues presented.
In the usual happy day scenario, this is always "good". If something
fails during or after a mode set, the kernel driver can set the link
status to "bad" and issue a hotplug uevent for userspace to have it
re-check the valid modes through GET_CONNECTOR IOCTL, and try modeset
again. If the theoretical capabilities of the link can't be reached,
the mode list is trimmed based on that.

v7 by Jani:
* Rebase, simplify set property while at it, checkpatch fix
v6:
* Fix a typo in kernel doc (Sean Paul)
v5:
* Clarify doc for silent rejection of atomic properties by driver (Daniel Vetter)
v4:
* Add comments in kernel-doc format (Daniel Vetter)
* Update the kernel-doc for link-status (Sean Paul)
v3:
* Fixed a build error (Jani Saarinen)
v2:
* Removed connector->link_status (Daniel Vetter)
* Set connector->state->link_status in drm_mode_connector_set_link_status_property
(Daniel Vetter)
* Set the connector_changed flag to true if connector->state->link_status changed.
* Reset link_status to GOOD in update_output_state (Daniel Vetter)
* Never allow userspace to set link status from Good To Bad (Daniel Vetter)

Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Tony Cheng <tony.cheng@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Eric Anholt <eric@anholt.net> (for the -modesetting patch)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/0182487051aa9f1594820e35a4853de2f8747b4e.1481883920.git.jani.nikula@intel.com
2017-02-27 10:24:25 +01:00
..
accessibility
acpi Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm 2017-02-06 19:36:04 -08:00
amba
android
ata ata: sata_mv:- Handle return value of devm_ioremap. 2017-01-06 15:45:32 -05:00
atm Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
auxdisplay auxdisplay: fix new ht16k33 build errors 2017-01-11 09:27:30 +01:00
base Merge branches 'pm-core-fixes' and 'pm-cpufreq-fixes' 2017-02-06 14:52:10 +01:00
bcma Revert "bcma: init serial console directly from ChipCommon code" 2017-01-17 14:23:44 +02:00
block xen-blkfront: correct maximum segment accounting 2017-01-23 13:27:42 -05:00
bluetooth Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-12-16 10:24:44 -08:00
bus cpu/hotplug: Cleanup state names 2016-12-25 10:47:44 +01:00
cdrom Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
char Linux 4.10-rc8 2017-02-23 12:10:12 +10:00
clk One fix for Samsung Exynos524x SoCs where recent IOMMU patches have 2017-01-21 18:46:45 -08:00
clocksource clocksource/exynos_mct: Clear interrupt when cpu is shut down 2017-01-17 10:08:38 +01:00
connector
cpufreq Merge branches 'pm-core-fixes' and 'pm-cpufreq-fixes' 2017-02-06 14:52:10 +01:00
cpuidle Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-02-06 14:16:23 -08:00
dax libnvdimm for 4.10 2016-12-18 15:49:10 -08:00
dca
devfreq PM / devfreq: exynos-bus: Fix the wrong return value 2017-01-03 00:21:45 +01:00
dio Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
dma dmaengine: pl330: fix double lock 2017-01-25 15:35:11 +05:30
dma-buf dma-buf/dma-fence: improve doc for dma_fence_add_callback() 2017-02-16 09:58:02 +05:30
edac Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
eisa
extcon extcon: return error code on failure 2017-01-11 09:11:39 +01:00
firewire
firmware efi/fdt: Avoid FDT manipulation after ExitBootServices() 2017-02-01 21:17:49 +01:00
fmc
fpga fpga: Clarify how write_init works streaming modes 2016-11-29 15:51:49 -06:00
gpio gpio: provide lockdep keys for nested/unnested irqchips 2017-01-19 09:57:20 +01:00
gpu drm: Add a new connector atomic property for link status 2017-02-27 10:24:25 +01:00
hid HID: cp2112: fix gpio-callback error handling 2017-01-31 12:59:33 +01:00
hsi
hv Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read() 2017-01-31 10:59:48 +01:00
hwmon hwmon: (lm90) fix temp1_max_alarm attribute 2017-01-02 10:15:28 -08:00
hwspinlock
hwtracing coresight/etm3/4x: Consolidate hotplug state space 2016-12-25 10:47:44 +01:00
i2c i2c: piix4: Request the SMBUS semaphore inside the mutex 2017-02-09 17:13:01 +01:00
ide Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
idle Power management material for v4.10-rc1 2016-12-13 10:41:53 -08:00
iio iio: dht11: Use usleep_range instead of msleep for start signal 2017-01-22 13:35:40 +00:00
infiniband IB/rxe: Fix mem_check_range integer overflow 2017-02-08 12:28:30 -05:00
input Input: synaptics-rmi4 - select 'SERIO' when needed 2017-02-07 14:31:45 -08:00
iommu IOMMU Fixes for Linux v4.10-rc2 2017-01-06 10:49:36 -08:00
ipack
irqchip irqchip/mxs: Enable SKIP_SET_WAKE and MASK_ON_SUSPEND 2016-12-31 19:06:44 +00:00
isdn ISDN: eicon: silence misleading array-bounds warning 2017-01-27 11:27:34 -05:00
leds cpu/hotplug: Cleanup state names 2016-12-25 10:47:44 +01:00
lguest Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
lightnvm Char/Misc driver patches for 4.10-rc1 2016-12-13 12:11:01 -08:00
macintosh Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mailbox ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
mcb
md dm crypt: replace RCU read-side section with rwsem 2017-02-03 10:26:14 -05:00
media media fixes for v4.10-rc8 2017-02-06 14:37:55 -08:00
memory Fixes for drivers already queued to prevent 2016-11-30 14:58:00 +01:00
memstick drivers/memstick/core/memstick.c: avoid -Wnonnull warning 2017-01-24 16:26:14 -08:00
message Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mfd - New Device Support 2016-12-19 08:16:26 -08:00
misc mei: bus: enable OS version only for SPT and newer 2017-01-11 07:43:57 +01:00
mmc mmc: mmci: avoid clearing ST Micro busy end interrupt mistakenly 2017-02-08 12:22:27 +01:00
mtd mtd: nand: lpc32xx: fix invalid error handling of a requested irq 2017-01-04 20:50:18 +01:00
net xen-netfront: Delete rx_refill_timer in xennet_disconnect_backend() 2017-02-10 13:44:49 -05:00
nfc
ntb ntb_transport: Remove unnecessary call to ntb_peer_spad_read 2016-12-23 16:11:07 -05:00
nubus Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
nvdimm libnvdimm, pfn: fix memmap reservation size versus 4K alignment 2017-02-04 14:47:31 -08:00
nvme nvme-fc: use blk_rq_nr_phys_segments 2017-01-26 17:49:14 +02:00
nvmem nvmem: fix nvmem_cell_read() return type doc 2017-01-04 18:22:47 +01:00
of pci-v4.10-changes 2016-12-15 12:46:48 -08:00
oprofile Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
parisc Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
parport parisc, parport_gsc: Fixes for printk continuation lines 2017-01-28 21:54:21 +01:00
pci Revert "PCI: pciehp: Add runtime PM support for PCIe hotplug ports" 2017-02-03 08:53:51 -06:00
pcmcia drivers/pcmcia/m32r_pcc.c: check return from add_pcc_socket 2016-12-12 18:55:06 -08:00
perf cpu/hotplug: Cleanup state names 2016-12-25 10:47:44 +01:00
phy SCSI misc on 20161213 2016-12-14 10:49:33 -08:00
pinctrl pinctrl: baytrail: Add missing spinlock usage in byt_gpio_irq_handler 2017-01-30 15:53:57 +01:00
platform platform/x86: ideapad-laptop: handle ACPI event 1 2017-01-22 12:47:06 +02:00
pnp Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
power ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
powercap powercap / RAPL: Add Knights Mill CPUID 2016-11-30 23:41:33 +01:00
pps
ps3
ptp Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-12 19:56:15 -08:00
pwm pwm: Changes for v4.10-rc1 2016-12-15 11:45:13 -08:00
rapidio
ras
regulator regulator: Fixes for v4.10 2017-02-03 13:46:38 -08:00
remoteproc Revert "remoteproc: Merge table_ptr and cached_table pointers" 2016-12-30 03:26:31 -08:00
reset ARM: SoC driver updates for v4.10 2016-12-15 16:03:25 -08:00
rpmsg rpmsg: virtio_rpmsg_bus: fix channel creation 2016-12-30 03:12:11 -08:00
rtc rtc: jz4740: make the driver buildable as a module again 2017-01-26 23:03:21 +01:00
s390 SCSI fixes on 20170210 2017-02-11 09:01:03 -08:00
sbus Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
scsi SCSI fixes on 20170210 2017-02-11 09:01:03 -08:00
sfi
sh lib: radix-tree: check accounting of existing slot replacement users 2016-12-12 18:55:08 -08:00
sn
soc soc: ti: wkup_m3_ipc: Fix error return code in wkup_m3_ipc_probe() 2017-01-12 13:37:49 -08:00
spi spi: Fixes for v4.10 2017-01-20 12:25:11 -08:00
spmi
ssb
staging mm: avoid returning VM_FAULT_RETRY from ->page_mkwrite handlers 2017-02-08 15:41:43 -08:00
target target: Fix COMPARE_AND_WRITE ref leak for non GOOD status 2017-02-08 08:25:39 -08:00
tc
thermal Revert "thermal: thermal_hwmon: Convert to hwmon_device_register_with_info()" 2017-01-25 09:51:08 +08:00
thunderbolt Char/Misc driver patches for 4.10-rc1 2016-12-13 12:11:01 -08:00
tty sysrq: attach sysrq handler correctly for 32-bit kernel 2017-01-11 09:22:54 +01:00
uio uio-hv-generic: store physical addresses instead of virtual 2016-12-10 14:57:58 +01:00
usb USB-serial fixes for v4.10-rc7 2017-02-03 22:19:15 +01:00
uwb
vfio vfio/spapr_tce: Set window when adding additional groups to container 2017-02-07 11:48:16 -07:00
vhost vhost: fix initialization for vq->is_le 2017-02-03 23:38:57 +02:00
video Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into drm-next 2017-01-27 11:00:42 +10:00
virt
virtio Revert "vring: Force use of DMA API for ARM-based systems with legacy devices" 2017-02-03 23:38:50 +02:00
vlynq
vme vme: Fix wrong pointer utilization in ca91cx42_slave_get 2017-01-11 10:42:16 +01:00
w1
watchdog Watchdog updates for v4.10 2016-12-24 11:27:45 -08:00
xen Merge branch 'stable/for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb 2017-01-27 12:17:07 -08:00
zorro Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
Kconfig
Makefile