With the recent exclusion of spi-bcm2708 from the 4.4 kernel, I'm left scratching my head as to whether or not pi4j's 1.1 release (or any other version) is capable of handling SPI.
Anybody else using this combination?
Related
I was wondering if there's a way for me to port kernel 5.10 to my device Google Pixel 3 (blueline) as the official Google support ended with kernel 4.9, but there's features that I need of kernel 5.10 that are not present in the kernel 4.9, so can you tell me how can I build kernel 5.10 for blueline? As far as I know, it is completely possible. By the way, I'm using Ubuntu 22.04 for all of this.
I tried using a GKI (Generic Kernel Image) of the kernel 5.10 with an Android 13 ROM but it didn't boot (i used both the boot.img and the uncompressed kernel image, none of them boots). I used fastboot to flash them:
fastboot flash boot boot.img
fastboot boot boot.img
it is not that straightforward. Please take a look at PostMarketOS
https://wiki.postmarketos.org/wiki/SDM845_Mainlining
and AOSP M:
https://github.com/aospm
I am going through the CXL support in Linux Kernel and I found that there is no function or support for cxl.cache. I'm confused if the cache part is not yet implemented in linux kernel or if the kernel should not have access to the cache commands?
(I have seen up to the latest Kernel release, 5.19)
I am using setcontext / getcontext for creating coroutines in C. The current software is implemented for ARMv7 using Linux 3.18 Kernel. Since these apis are deprecated, i couldn't find proper information regarding to their development status. I have read that they are reimplemented for ARM but deprecated on x86 oses. However, i can still find up-to-date Man pages for FreeBSD and Linux. There aren't any warnings or notices regarding to their use.
Is it a reliable choice to continue using them ? Why do they still exists in libc ? What is the status in Linux kernel 4 ?
Thanks
Can anybody tell me what's the difference in supporting I2C between kernels until and after 3.10 version?
Looks like after 3.10 something changed but I can't realize what exactly. I'm working on Intel Core-i5 2500k CPU with integrated video and am using ddccontrol tool to change brightness on my monitor. But if on kernel 3.2.32 I can do that, since 3.10.5 I2C support seems to be broken.
I don't know what exactly changed, but there are outputs from old and new kernels (i2cdetect -l):
3.2.32: http://pastebin.com/SqDPcwS9
3.10.5: http://pastebin.com/YCTmX90m
If on 3.2.32 I was able to use i2c-4 device to control my monitor, then on 3.10.5 list of i2c devices is shorter, and I don't see any GPIO buses (or what does it mean). On 3.10.5 system detects only monitor on i2c-1 but says that there is no support of DDC/CI on that device (http://pastebin.com/vZ4bALmt). For 3.2.32 everything is OK: http://pastebin.com/QL0fAZVC
Maybe I don't know something, e.g. some new config option have been added/changed in kernel.
Seems I'm not alone in my trouble - there are a lot of questions about I2C and ddccontrol around the web, but there are still no answer.
Need your help, really...
Thanks!
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UPD: on kernel 3.7 I've watched the same behavior as on 3.10, so, the breakage isn't at 3.10 but a bit earlier
I'm not sure, but I think this has been fixed in commit 59b016fe8fe83920e8717163289e61ab8e327b90 the 17.10.2013
Can you try a more recent kernel (3.12) ?
What is kernel's KMS(kernel mode setting) API?
ModeSetting does refer to the graphic stack. It is the process of setting up the clocks and scanout buffers, initialize the chips, lighting up the displays and so on.
The kernel subsystem responsible for this is the DRM subsystem. It has a userspace library that is developed in lock-step with the kernel part and allows i.e. Xorg access to the userland facing part of the interface (normally called ABI). The hardware-facing side of the kernel interface is usually referred to as the API.
Specifically you can use the 'xrandr' binary to instruct XOrg via the randr-protocol to instruct the kernel to change the mode. That binary is installed alongside the X server and also gives you some information about the graphics card and the current mode.
The DRM ModeSetting API is IOCTL based and the following site gives an technical overview: http://dri.freedesktop.org/wiki/DrmModesetting
Also the documentation in the current linux-3.7 releases is quite improved. To check that out, you have to fetch the latest kernel sources, and then, in the kernel sourcetree do
$ make htmldocs
and then look at the generated file Documentation/DocBook/drm/index.html .
Hth
Mode setting is usually related to Graphics setup.
A reference article dated April 19, 2008 notes,
kernel mode-setting involves moving the mode-setting code for video adapters from the user-space X server drivers into the Linux kernel. This may seem like an uninteresting topic for end-users, but having the mode-setting done in the kernel allows for a cleaner and richer boot process, improved suspend and resume support, and more reliable VT switching (along with other advantages). Kernel mode-setting isn't yet in the mainline Linux kernel nor is the API for it frozen, but Fedora 9 shipping next month will be the first major distribution carrying this initial support. In this article we're looking more closely at kernel mode-setting with the Intel X.Org driver as well as showing videos of kernel-based mode-setting in action.
Here is a Fedora wiki KernelModesetting page.