Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Clone this repository
For self-hosted knots, clone URLs may differ based on your setup.
Download tar.gz
Pull drm fixes from Dave Airlie:
"Three final fixes, one for a feature that is new in this kernel, one
bochs fix for qemu riscv and one atomic modesetting fix.
I've left a few of the other late fixes until next as I didn't want to
throw in anything that wasn't really necessary"
* tag 'drm-fixes-2019-03-01' of git://anongit.freedesktop.org/drm/drm:
drm/bochs: Fix the ID mismatch error
drm: Block fb changes for async plane updates
drm/amd/display: Use vrr friendly pageflip throttling in DC.
Pull MIPS fixes from Paul Burton:
"A few more MIPS fixes:
- Fix 16b cmpxchg() operations which could erroneously fail if bits
15:8 of the old value are non-zero. In practice I'm not aware of
any actual users of 16b cmpxchg() on MIPS, but this fixes the
support for it was was introduced in v4.13.
- Provide a struct device to dma_alloc_coherent for Lantiq XWAY
systems with a "Voice MIPS Macro Core" (VMMC) device.
- Provide DMA masks for BCM63xx ethernet devices, fixing a regression
introduced in v4.19.
- Fix memblock reservation for the kernel when the system has a
non-zero PHYS_OFFSET, correcting the memblock conversion performed
in v4.20"
* tag 'mips_fixes_5.0_4' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
MIPS: fix memory setup for platforms with PHYS_OFFSET != 0
MIPS: BCM63XX: provide DMA masks for ethernet devices
MIPS: lantiq: pass struct device to DMA API functions
MIPS: fix truncation in __cmpxchg_small for short values
When running RISC-V QEMU with the Bochs device attached via PCIe the
probe of the Bochs device fails with:
[drm:bochs_hw_init] *ERROR* ID mismatch
This was introduced by this commit:
7780eb9ce8 bochs: convert to drm_dev_register
To fix the error we ensure that pci_enable_device() is called before
bochs_load().
Fixes: 7780eb9ce80f ("bochs: convert to drm_dev_register")
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reported-by: David Abdurachmanov <david.abdurachmanov@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20190221003231.31625-1-alistair.francis@wdc.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Pull orangefs fixlet from Mike Marshall:
"Remove two un-needed BUG_ONs"
* tag 'for-linus-5.0-ofs1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux:
orangefs: remove two un-needed BUG_ONs...
For platforms, which use a PHYS_OFFSET != 0, symbol _end also
contains that offset. So when calling memblock_reserve() for
reserving kernel the size argument needs to be adjusted.
Fixes: bcec54bf3118 ("mips: switch to NO_BOOTMEM")
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # v4.20+
The prepare_fb call always happens on new_plane_state.
The drm_atomic_helper_cleanup_planes checks to see if
plane state pointer has changed when deciding to call cleanup_fb on
either the new_plane_state or the old_plane_state.
For a non-async atomic commit the state pointer is swapped, so this
helper calls prepare_fb on the new_plane_state and cleanup_fb on the
old_plane_state. This makes sense, since we want to prepare the
framebuffer we are going to use and cleanup the the framebuffer we are
no longer using.
For the async atomic update helpers this differs. The async atomic
update helpers perform in-place updates on the existing state. They call
drm_atomic_helper_cleanup_planes but the state pointer is not swapped.
This means that prepare_fb is called on the new_plane_state and
cleanup_fb is called on the new_plane_state (not the old).
In the case where old_plane_state->fb == new_plane_state->fb then
there should be no behavioral difference between an async update
and a non-async commit. But there are issues that arise when
old_plane_state->fb != new_plane_state->fb.
The first is that the new_plane_state->fb is immediately cleaned up
after it has been prepared, so we're using a fb that we shouldn't
be.
The second occurs during a sequence of async atomic updates and
non-async regular atomic commits. Suppose there are two framebuffers
being interleaved in a double-buffering scenario, fb1 and fb2:
- Async update, oldfb = NULL, newfb = fb1, prepare fb1, cleanup fb1
- Async update, oldfb = fb1, newfb = fb2, prepare fb2, cleanup fb2
- Non-async commit, oldfb = fb2, newfb = fb1, prepare fb1, cleanup fb2
We call cleanup_fb on fb2 twice in this example scenario, and any
further use will result in use-after-free.
The simple fix to this problem is to block framebuffer changes
in the drm_atomic_helper_async_check function for now.
v2: Move check by itself, add a FIXME (Daniel)
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Cc: <stable@vger.kernel.org> # v4.14+
Fixes: fef9df8b5945 ("drm/atomic: initial support for asynchronous plane update")
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Acked-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Link: https://patchwork.freedesktop.org/patch/275364/
Signed-off-by: Dave Airlie <airlied@redhat.com>
Pull MMC fixes from Ulf Hansson:
"MMC core:
- Fix NULL ptr crash for a special test case
- Align max segment size with logical block size to prevent bugs in
v5.1-rc1.
MMC host:
- cqhci: Minor fixes
- tmio: Prevent interrupt storm
- tmio: Fixup SD/MMC card initialization
- spi: Allow card to be detected during probe
- sdhci-esdhc-imx: Fixup fix for ERR004536"
* tag 'mmc-v5.0-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
mmc: sdhci-esdhc-imx: correct the fix of ERR004536
mmc: core: align max segment size with logical block size
mmc: cqhci: Fix a tiny potential memory leak on error condition
mmc: cqhci: fix space allocated for transfer descriptor
mmc: core: Fix NULL ptr crash from mmc_should_fail_request
mmc: tmio: fix access width of Block Count Register
mmc: tmio_mmc_core: don't claim spurious interrupts
mmc: spi: Fix card detection during probe
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
The switch to the generic dma ops made dma masks mandatory, breaking
devices having them not set. In case of bcm63xx, it broke ethernet with
the following warning when trying to up the device:
[ 2.633123] ------------[ cut here ]------------
[ 2.637949] WARNING: CPU: 0 PID: 325 at ./include/linux/dma-mapping.h:516 bcm_enetsw_open+0x160/0xbbc
[ 2.647423] Modules linked in: gpio_button_hotplug
[ 2.652361] CPU: 0 PID: 325 Comm: ip Not tainted 4.19.16 #0
[ 2.658080] Stack : 80520000 804cd3ec 00000000 00000000 804ccc00 87085bdc 87d3f9d4 804f9a17
[ 2.666707] 8049cf18 00000145 80a942a0 00000204 80ac0000 10008400 87085b90 eb3d5ab7
[ 2.675325] 00000000 00000000 80ac0000 000022b0 00000000 00000000 00000007 00000000
[ 2.683954] 0000007a 80500000 0013b381 00000000 80000000 00000000 804a1664 80289878
[ 2.692572] 00000009 00000204 80ac0000 00000200 00000002 00000000 00000000 80a90000
[ 2.701191] ...
[ 2.703701] Call Trace:
[ 2.706244] [<8001f3c8>] show_stack+0x58/0x100
[ 2.710840] [<800336e4>] __warn+0xe4/0x118
[ 2.715049] [<800337d4>] warn_slowpath_null+0x48/0x64
[ 2.720237] [<80289878>] bcm_enetsw_open+0x160/0xbbc
[ 2.725347] [<802d1d4c>] __dev_open+0xf8/0x16c
[ 2.729913] [<802d20cc>] __dev_change_flags+0x100/0x1c4
[ 2.735290] [<802d21b8>] dev_change_flags+0x28/0x70
[ 2.740326] [<803539e0>] devinet_ioctl+0x310/0x7b0
[ 2.745250] [<80355fd8>] inet_ioctl+0x1f8/0x224
[ 2.749939] [<802af290>] sock_ioctl+0x30c/0x488
[ 2.754632] [<80112b34>] do_vfs_ioctl+0x740/0x7dc
[ 2.759459] [<80112c20>] ksys_ioctl+0x50/0x94
[ 2.763955] [<800240b8>] syscall_common+0x34/0x58
[ 2.768782] ---[ end trace fb1a6b14d74e28b6 ]---
[ 2.773544] bcm63xx_enetsw bcm63xx_enetsw.0: cannot allocate rx ring 512
Fix this by adding appropriate DMA masks for the platform devices.
Fixes: f8c55dc6e828 ("MIPS: use generic dma noncoherent ops for simple noncoherent platforms")
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: stable@vger.kernel.org # v4.19+
Fix for variable refresh rate stuttering
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Alex Deucher <alexdeucher@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190227192115.14597-1-alexander.deucher@amd.com
Pull crypto fixes from Herbert Xu:
"This fixes a compiler warning introduced by a previous fix, as well as
two crash bugs on ARM"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: sha512/arm - fix crash bug in Thumb2 build
crypto: sha256/arm - fix crash bug in Thumb2 build
crypto: ccree - add missing inline qualifier
Commit 18094430d6b5 ("mmc: sdhci-esdhc-imx: add ADMA Length
Mismatch errata fix") involve the fix of ERR004536, but the
fix is incorrect. Double confirm with IC, need to clear the
bit 7 of register 0x6c rather than set this bit 7.
Here is the definition of bit 7 of 0x6c:
0: enable the new IC fix for ERR004536
1: do not use the IC fix, keep the same as before
Find this issue on i.MX845s-evk board when enable CMDQ, and
let system in heavy loading.
root@imx8mmevk:~# dd if=/dev/mmcblk2 of=/dev/null bs=1M &
root@imx8mmevk:~# memtester 1000M > /dev/zero &
root@imx8mmevk:~# [ 139.897220] mmc2: cqhci: timeout for tag 16
[ 139.901417] mmc2: cqhci: ============ CQHCI REGISTER DUMP ===========
[ 139.907862] mmc2: cqhci: Caps: 0x0000310a | Version: 0x00000510
[ 139.914311] mmc2: cqhci: Config: 0x00001001 | Control: 0x00000000
[ 139.920753] mmc2: cqhci: Int stat: 0x00000000 | Int enab: 0x00000006
[ 139.927193] mmc2: cqhci: Int sig: 0x00000006 | Int Coal: 0x00000000
[ 139.933634] mmc2: cqhci: TDL base: 0x7809c000 | TDL up32: 0x00000000
[ 139.940073] mmc2: cqhci: Doorbell: 0x00030000 | TCN: 0x00000000
[ 139.946518] mmc2: cqhci: Dev queue: 0x00010000 | Dev Pend: 0x00010000
[ 139.952967] mmc2: cqhci: Task clr: 0x00000000 | SSC1: 0x00011000
[ 139.959411] mmc2: cqhci: SSC2: 0x00000001 | DCMD rsp: 0x00000000
[ 139.965857] mmc2: cqhci: RED mask: 0xfdf9a080 | TERRI: 0x00000000
[ 139.972308] mmc2: cqhci: Resp idx: 0x0000002e | Resp arg: 0x00000900
[ 139.978761] mmc2: sdhci: ============ SDHCI REGISTER DUMP ===========
[ 139.985214] mmc2: sdhci: Sys addr: 0xb2c19000 | Version: 0x00000002
[ 139.991669] mmc2: sdhci: Blk size: 0x00000200 | Blk cnt: 0x00000400
[ 139.998127] mmc2: sdhci: Argument: 0x40110400 | Trn mode: 0x00000033
[ 140.004618] mmc2: sdhci: Present: 0x01088a8f | Host ctl: 0x00000030
[ 140.011113] mmc2: sdhci: Power: 0x00000002 | Blk gap: 0x00000080
[ 140.017583] mmc2: sdhci: Wake-up: 0x00000008 | Clock: 0x0000000f
[ 140.024039] mmc2: sdhci: Timeout: 0x0000008f | Int stat: 0x00000000
[ 140.030497] mmc2: sdhci: Int enab: 0x107f4000 | Sig enab: 0x107f4000
[ 140.036972] mmc2: sdhci: AC12 err: 0x00000000 | Slot int: 0x00000502
[ 140.043426] mmc2: sdhci: Caps: 0x07eb0000 | Caps_1: 0x8000b407
[ 140.049867] mmc2: sdhci: Cmd: 0x00002c1a | Max curr: 0x00ffffff
[ 140.056314] mmc2: sdhci: Resp[0]: 0x00000900 | Resp[1]: 0xffffffff
[ 140.062755] mmc2: sdhci: Resp[2]: 0x328f5903 | Resp[3]: 0x00d00f00
[ 140.069195] mmc2: sdhci: Host ctl2: 0x00000008
[ 140.073640] mmc2: sdhci: ADMA Err: 0x00000007 | ADMA Ptr: 0x7809c108
[ 140.080079] mmc2: sdhci: ============================================
[ 140.086662] mmc2: running CQE recovery
Fixes: 18094430d6b5 ("mmc: sdhci-esdhc-imx: add ADMA Length Mismatch errata fix")
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
The DMA API generally relies on a struct device to work properly, and
only barely works without one for legacy reasons. Pass the easily
available struct device from the platform_device to remedy this.
Also use GFP_KERNEL instead of GFP_ATOMIC as the gfp_t for the memory
allocation, as we aren't in interrupt context or under a lock.
Note that this whole function looks somewhat bogus given that we never
even look at the returned dma address, and the CPHYSADDR magic on
a returned noncached mapping looks "interesting". But I'll leave
that to people more familiar with the code to sort out.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: John Crispin <john@phrozen.org>
Cc: Vinod Koul <vkoul@kernel.org>
Cc: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: dmaengine@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Cc: linux-fbdev@vger.kernel.org
Cc: alsa-devel@alsa-project.org
Cc: iommu@lists.linux-foundation.org