tjh.dev
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.
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1444015
3
928
Clone this repository
https://tangled.org/tjh.dev/kernel
https://tangled.org/did:plc:65gha4t3avpfpzmvpbwovss7/kernel
git@gordian.tjh.dev:tjh.dev/kernel
git@gordian.tjh.dev:did:plc:65gha4t3avpfpzmvpbwovss7/kernel
For self-hosted knots, clone URLs may differ based on your setup.
Download tar.gz
Pull iommu fixes from Joerg Roedel:
- Two fixes for VT-d and generic IOMMU code to fix teardown on error
handling code paths.
- Patch for the Intel VT-d driver to fix handling of non-PCI devices
- Fix W=1 compile warning in dma-iommu code
* tag 'iommu-fixes-v5.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
iommu/dma: fix variable 'cookie' set but not used
iommu/vt-d: Unlink device if failed to add to group
iommu: Remove device link to group on failure
iommu/vt-d: Fix adding non-PCI devices to Intel IOMMU
Pull i2c fixes from Wolfram Sang:
"Two driver bugfixes, a documentation fix, and a removal of a spec
violation for the bus recovery algorithm in the core"
* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: fix bus recovery stop mode timing
i2c: bcm2835: Store pointer to bus clock
dt-bindings: i2c: at91: fix i2c-sda-hold-time-ns documentation for sam9x60
i2c: at91: fix clk_offset for sam9x60
The commit c18647900ec8 ("iommu/dma: Relax locking in
iommu_dma_prepare_msi()") introduced a compliation warning,
drivers/iommu/dma-iommu.c: In function 'iommu_dma_prepare_msi':
drivers/iommu/dma-iommu.c:1206:27: warning: variable 'cookie' set but
not used [-Wunused-but-set-variable]
struct iommu_dma_cookie *cookie;
^~~~~~
Fixes: c18647900ec8 ("iommu/dma: Relax locking in iommu_dma_prepare_msi()")
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Pull thread fixes from Christian Brauner:
"This contains a series of patches to fix CLONE_SETTLS when used with
clone3().
The clone3() syscall passes the tls argument through struct clone_args
instead of a register. This means, all architectures that do not
implement copy_thread_tls() but still support CLONE_SETTLS via
copy_thread() expecting the tls to be located in a register argument
based on clone() are currently unfortunately broken. Their tls value
will be garbage.
The patch series fixes this on all architectures that currently define
__ARCH_WANT_SYS_CLONE3. It also adds a compile-time check to ensure
that any architecture that enables clone3() in the future is forced to
also implement copy_thread_tls().
My ultimate goal is to get rid of the copy_thread()/copy_thread_tls()
split and just have copy_thread_tls() at some point in the not too
distant future (Maybe even renaming copy_thread_tls() back to simply
copy_thread() once the old function is ripped from all arches). This
is dependent now on all arches supporting clone3().
While all relevant arches do that now there are still four missing:
ia64, m68k, sh and sparc. They have the system call reserved, but not
implemented. Once they all implement clone3() we can get rid of
ARCH_WANT_SYS_CLONE3 and HAVE_COPY_THREAD_TLS.
This series also includes a minor fix for the arm64 uapi headers which
caused __NR_clone3 to be missing from the exported user headers.
Unfortunately the series came in a little late especially given that
it touches a range of architectures. Due to the holidays not all arch
maintainers responded in time probably due to their backlog. Will and
Arnd have thankfully acked the arm specific changes.
Given that the changes are straightforward and rather minimal combined
with the fact the that clone3() with CLONE_SETTLS is broken I decided
to send them post rc3 nonetheless"
* tag 'clone3-tls-v5.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
um: Implement copy_thread_tls
clone3: ensure copy_thread_tls is implemented
xtensa: Implement copy_thread_tls
riscv: Implement copy_thread_tls
parisc: Implement copy_thread_tls
arm: Implement copy_thread_tls
arm64: Implement copy_thread_tls
arm64: Move __ARCH_WANT_SYS_CLONE3 definition to uapi headers
The I2C specification states that tsu:sto for standard mode timing must
be at minimum 4us. Pictographically, this is:
SCL: ____/~~~~~~~~~
SDA: _________/~~~~
->| |<- 4us minimum
We are currently waiting 2.5us between asserting SCL and SDA, which is
in violation of the standard. Adjust the timings to ensure that we meet
what is stipulated as the minimum timings to ensure that all devices
correctly interpret the STOP bus transition.
This is more important than trying to generate a square wave with even
duty cycle.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
If the device fails to be added to the group, make sure to unlink the
reference before returning.
Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Fixes: 39ab9555c2411 ("iommu: Add sysfs bindings for struct iommu_device")
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Pull HID fix from Jiri Kosina:
"A regression fix for EPOLLOUT handling in hidraw and uhid"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid:
HID: hidraw, uhid: Always report EPOLLOUT
This is required for clone3 which passes the TLS value through a
struct rather than a register.
Signed-off-by: Amanieu d'Antras <amanieu@gmail.com>
Cc: linux-um@lists.infradead.org
Cc: <stable@vger.kernel.org> # 5.3.x
Link: https://lore.kernel.org/r/20200104123928.1048822-1-amanieu@gmail.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
The commit bebff81fb8b9 ("i2c: bcm2835: Model Divider in CCF") introduced
a NULL pointer dereference on driver unload. It seems that we can't fetch
the bus clock via devm_clk_get in bcm2835_i2c_remove. As an alternative
approach store a pointer to the bus clock in the private driver structure.
Fixes: bebff81fb8b9 ("i2c: bcm2835: Model Divider in CCF")
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This adds the missing teardown step that removes the device link from
the group when the device addition fails.
Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Fixes: 797a8b4d768c5 ("iommu: Handle default domain attach failure")
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Pull USB/PHY fixes from Greg KH:
"Here are a number of USB and PHY driver fixes for 5.5-rc6
Nothing all that unusual, just the a bunch of small fixes for a lot of
different reported issues. The PHY driver fixes are in here as they
interacted with the usb drivers.
Full details of the patches are in the shortlog, and all of these have
been in linux-next with no reported issues"
* tag 'usb-5.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (24 commits)
usb: missing parentheses in USE_NEW_SCHEME
usb: ohci-da8xx: ensure error return on variable error is set
usb: musb: Disable pullup at init
usb: musb: fix idling for suspend after disconnect interrupt
usb: typec: ucsi: Fix the notification bit offsets
USB: Fix: Don't skip endpoint descriptors with maxpacket=0
USB-PD tcpm: bad warning+size, PPS adapters
phy/rockchip: inno-hdmi: round clock rate down to closest 1000 Hz
usb: chipidea: host: Disable port power only if previously enabled
usb: cdns3: should not use the same dev_id for shared interrupt handler
usb: dwc3: gadget: Fix request complete check
usb: musb: dma: Correct parameter passed to IRQ handler
usb: musb: jz4740: Silence error if code is -EPROBE_DEFER
usb: udc: tegra: select USB_ROLE_SWITCH
USB: core: fix check for duplicate endpoints
phy: cpcap-usb: Drop extra write to usb2 register
phy: cpcap-usb: Improve host vs docked mode detection
phy: cpcap-usb: Prevent USB line glitches from waking up modem
phy: mapphone-mdm6600: Fix uninitialized status value regression
phy: cpcap-usb: Fix flakey host idling and enumerating of devices
...
hidraw and uhid device nodes are always available for writing so we should
always report EPOLLOUT and EPOLLWRNORM bits, not only in the cases when
there is nothing to read.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes: be54e7461ffdc ("HID: uhid: Fix returning EPOLLOUT from uhid_char_poll")
Fixes: 9f3b61dc1dd7b ("HID: hidraw: Fix returning EPOLLOUT from hidraw_poll")
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
copy_thread implementations handle CLONE_SETTLS by reading the TLS
value from the registers containing the syscall arguments for
clone. This doesn't work with clone3 since the TLS value is passed
in clone_args instead.
Signed-off-by: Amanieu d'Antras <amanieu@gmail.com>
Cc: <stable@vger.kernel.org> # 5.3.x
Link: https://lore.kernel.org/r/20200102172413.654385-8-amanieu@gmail.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
README