spi: Inquiry Regarding Linux Kernel SPI Subsystem device drivers

Hi all, I hope this email finds you well. I am new to the Linux kernel SPI subsystem, I am currently in the process of learning about its functionalities and intricacies. I have a few doubts and questions that I would like to clarify, and I am hoping you could provide some assistance. As I unders

PCI: latency

[ Please keep me in CC as I'm not subscribed to the list] Hi all, We are using the Linux OS on an x86_64 machine. I need to measure the PCIe latency on my system, does kernel have any latency measurement module for the PCIe bus? Thanks, ___ Kernelnew

Re: Embedded USB Debug(EUD) driver

On Sat, Jul 31, 2021 at 11:12 AM Greg KH wrote: > > On Fri, Jul 30, 2021 at 11:33:09PM +0530, Subhashini Rao Beerisetty wrote: > > Hi All, > > > > I'm currently looking for the Embedded USB Debug (EUD) interface driver. > > For what specific hardware? Do you h

Embedded USB Debug(EUD) driver

Hi All, I'm currently looking for the Embedded USB Debug (EUD) interface driver. Does it available in any of the kernel tree? Thanks ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelne

Re: cpu-freq: running the perf increases the data rate?

On Fri, Aug 28, 2020 at 6:04 PM Artem Bityutskiy wrote: > > On Thu, 2020-08-27 at 22:25 +0530, Subhashini Rao Beerisetty wrote: > > I have an application which finds the data rate over the PCIe > > interface. I’m getting the lesser data rate in one of my Linux X86 > >

cpu-freq: running the perf increases the data rate?

[ Please keep me in CC as I'm not subscribed to the list] Hi all, I have an application which finds the data rate over the PCIe interface. I’m getting the lesser data rate in one of my Linux X86 systems. When I change the scaling_governor from "powersave" to "performance" mode for each CPU, then

test tools to measure performance of the Linux kernel

Hi all, I’m having a few Linux x86_64 systems(same hardware configuration) with different Ubuntu kernels installed on those machines. I’m looking for any existing test suite which can be used to measure the system performance on different kernels. Any pointers on this topic will be greatly appr

Re: general protection fault vs Oops

On Mon, May 18, 2020 at 2:16 AM Cong Wang wrote: > > On Sat, May 16, 2020 at 9:16 AM Subhashini Rao Beerisetty > wrote: > > Yes, those are out-of-tree modules. Basically, my question is, in > > general what is the difference between 'general protection fault' a

Re: general protection fault vs Oops

On Sat, May 16, 2020 at 9:29 PM Randy Dunlap wrote: > > On 5/16/20 6:53 AM, Valdis Klētnieks wrote: > > On Sat, 16 May 2020 18:05:07 +0530, Subhashini Rao Beerisetty said: > > > >> In the first attempt when I run that test case I landed into “general > >

Re: general protection fault vs Oops

On Sat, May 16, 2020 at 7:23 PM Valdis Klētnieks wrote: > > On Sat, 16 May 2020 18:05:07 +0530, Subhashini Rao Beerisetty said: > > > In the first attempt when I run that test case I landed into “general > > protection fault: [#1] SMP" .. Next I rebooted and ran t

general protection fault vs Oops

Hi all, In my Linux box, I see that kernel crashes for a known test case. In the first attempt when I run that test case I landed into “general protection fault: [#1] SMP" .. Next I rebooted and ran the same test , but now it resulted the “Oops: 0002 [#1] SMP". In both cases the call trace l

Crash dump?

Hi all, In Kernel, what needs to be configured to get the crash dump? Can someone clarify me with the sequence of steps to get the crash dump.. Thanks, ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mail

Re: sound over USB

On Wed, May 13, 2020 at 8:53 PM Sid Spry wrote: > > On Tue, May 12, 2020, at 11:43 AM, Subhashini Rao Beerisetty wrote> > > > > How do I use it for playing and recording an audio? > > > > Basically first I want to gain knowledge on set of test cases I can &g

sound over USB

Hi all, In my Linux machine, I connected the plantronics usb headset with mic and I see(with the help of dmesg) that this device detected. [116676.507868] usb 2-2: new full-speed USB device number 5 using xhci_hcd [116676.923445] usb 2-2: New USB device found, idVendor=047f, idProduct=c012 [1

soft lockup in fb_flashcursor

Hi All, I noticed soft lockup in fb_flashcursor(). What could be the problem? and how to resolve this? [ 1061.790322] NMI watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [kworker/u8:1:2690] [ 1061.790380] Modules linked in: debug(OE) opabs(OE) gpio(OE) ramoops reed_solomon ppdev intel_rapl inte

Re: How to debug throughput issues?

On Wed, Jun 26, 2019 at 11:17 AM hariprasad kelam wrote: > > Hi subhashini, > > On Wed, 26 Jun, 2019, 10:56 AM Subhashini Rao Beerisetty, > wrote: >> >> On Wed, Jun 26, 2019 at 7:44 AM Hariprasad Kelam >> wrote: >> > >> > On Tue, Jun 25,

Re: How to debug throughput issues?

On Wed, Jun 26, 2019 at 7:44 AM Hariprasad Kelam wrote: > > On Tue, Jun 25, 2019 at 10:26:54PM +0530, Subhashini Rao Beerisetty wrote: > Hi Subhashini, > > Please see inline, > > Hi All, > > > > I’ve two Bluetooth dongles and connected to two Linux > >

How to debug throughput issues?

Hi All, I’ve two Bluetooth dongles and connected to two Linux systems(hostname1, hostname2). I’ve a test executable and it creates a BT link does the file transfer and calculates the throughput. I repeated the same test with the same BT dongles on another different Linux systems(hostname3, hos

Re: how long wait_for_completion_interruptible_timeout() blocks

On Thu, Jun 20, 2019 at 11:38 AM anish singh wrote: > > > > On Wed, Jun 19, 2019 at 10:47 PM Subhashini Rao Beerisetty > wrote: >> >> Hi All, >> >> I’ve two Linux systems, I tried to measure how long >> wait_for_completion_interruptible_timeout

how long wait_for_completion_interruptible_timeout() blocks

Hi All, I’ve two Linux systems, I tried to measure how long wait_for_completion_interruptible_timeout() blocked after completion is signaled by complete() call. I noticed two different results in both systems. In one system I noticed this duration in between 10 to 60 micro seconds, where as in ot

tty: uart: loopback test

Hi All, I’m looking for an userspace ‘C’ test code to transfer a file on UART Tx line and receive the file on UART Rx line to test loopback supported serial port. Can anybody give example of such application? Thanks ___ Kernelnewbies mailing list

Re: tty: uart: custom speed

On Mon, Mar 4, 2019 at 8:27 PM Greg KH wrote: > > On Mon, Mar 04, 2019 at 08:19:44PM +0530, Subhashini Rao Beerisetty wrote: > > On Mon, Mar 4, 2019 at 6:53 PM Greg KH wrote: > > > > > > On Mon, Mar 04, 2019 at 05:46:54PM +0530, Subhashini Rao Beer

Re: tty: uart: custom speed

On Mon, Mar 4, 2019 at 6:53 PM Greg KH wrote: > > On Mon, Mar 04, 2019 at 05:46:54PM +0530, Subhashini Rao Beerisetty wrote: > > Hi All, > > > > > > I’ve an UART ports on Xilinx FPGA board and it gets connected to PC > > via PCIe bus. I could not find any

tty: uart: custom speed

Hi All, I’ve an UART ports on Xilinx FPGA board and it gets connected to PC via PCIe bus. I could not find any kernel serial driver which supports our hardware so I plan to develop a new driver. I see two approaches to develop an UART driver i.e. either by using tty_register_driver() or an uart_

gpio: struct gpio_chip.set_multiple\get_multiple

Hi All, struct gpio_chip { int (*get_multiple)(struct gpio_chip *chip,unsigned long *mask, unsigned long *bits); void (*set_multiple)(struct gpio_chip *chip,unsigned long *mask, unsigned long *bits); } struct gpio_chip provides set_multiple callback to assign output values for multiple si

IOCtl argument check

Hi All, Can someone clarify me on IOCtl argument check. Kernel code has few IOCtl’s with a pointer to structure as an arguments. For example please consider the below mentioned IOCtl’s. #define MB862XX_L1_SET_CFG _IOW(MB862XX_BASE, 1, struct mb862xx_l1_cfg*) #define MB862XX_L1_GET_CFG _IO

gpio: userspace tools

Hi All, I’m using v4.4 kernel and I see that gpiochipN are created under /sys/class/gpio. Latest kernel has three tools lsgpio, gpio-hammer and gpio-event-mon, all these tools opens the device node under /dev/gpiochipN. Does v4.4 kernel has any similar tools to control GPIO pins by using /sys/cla

System call vs POSIX call

Hi All, I'm trying to get the difference between system call and POSIX call. System calls are user mode API's (open(), close(), ioctl(),...) gets the kernel service via software interrupt. What about POSIX calls and how it differs with the system call.? Can anyone clarify me on this. _

Re: clk: timestamps

On Wed, Jun 27, 2018 at 1:17 PM, Yann Droneaud wrote: > Hi, > > Le mardi 26 juin 2018 à 19:44 +0530, Subhashini Rao Beerisetty a > écrit : > > > > In the kernel code I see it supports CLOCK_REALTIME \ CLOCK_MONOTONIC > > \ CLOCK_MONOTONIC_RAW timestamps. Ca

clk: timestamps

Hi All, In the kernel code I see it supports CLOCK_REALTIME \ CLOCK_MONOTONIC \ CLOCK_MONOTONIC_RAW timestamps. Can someone explain what’s major difference between those three modes and when to use which one? I’ve N number of Linux machines in the network with the same software running. Basical

Re: audio samples data flow from user mode to kernel mode

On Sat, Jun 23, 2018 at 4:41 PM, wrote: > > > 23.06.2018, 14:52, "Subhashini Rao Beerisetty" < > subhashbeerise...@gmail.com>: > > Hello All, > > Hello, > > > > I’m trying to understand how audio samples transferred between user mode > to k

audio samples data flow from user mode to kernel mode

Hello All, I’m trying to understand how audio samples transferred between user mode to kernel mode during playback and capture. I’m using aplay & arecord alsa utilities for playback and capture. Let us take a PCM wav file of sample rate 48000 and it has a total number of samples 48 (Appro

Re: Main Linux kernel vs Ubuntu kernel

My question related to backward compatibility is: If an API’s signature changed from kernel version x.y.z onwards, does the mainline tree code uses the below mentioned logic? #if LINUX_VERSION_CODE >= KERNEL_VERSION(x,y,z) #else #endif Regarding long term release kernels, what here ‘long ter

Main Linux kernel vs Ubuntu kernel

Hi All, Apologies for the dull questions, I’m noob, need to learn lot more stuff. We’ve a bunch of hardware & test systems, we started this project by opting ubuntu distro 16.04 LTS v4.4 kernel for development of device drivers, test utilities. I’d like to know, what are the differences betw