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

Hi Subhashini, On Sat, Jun 23, 2018 at 4:22 PM, Subhashini Rao Beerisetty wrote: > 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. > > > >

Re: How kernel derive irq number for particular irq line

Hi Abhinav, On Mon, Jun 25, 2018 at 12:17 AM, Abhinav Misra wrote: > Hi Guys, > > I want to know how the irq number is derived in linux kernel. > In kernel we are using below function for registering ISR. > For platform drivers, usually this information comes from the device tree entry. which yo

Re: Question regarding dynamic allocated tasklet

Hi Abhinav, On Sat, Jun 16, 2018 at 11:52 PM, Abhinav Misra wrote: > > Hi Guys, > > I am Abhinav, new to this mailing list. > > Have some query on tasklet. > Going Jerry Cooperstein's LDD book chapter-20 (Interrupt handling and > deferrable functions) lab exercises. > > Attached is the snapshot

How to debug when IRQs are disabled for few milliseconds?

t succeed in this. I have also tried to use ftrace, however it was very difficult to find out where exactly the IRQs are getting disabled. Can anyone help? Regards, Priyaranjan ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.

OOM while increasing RAM to 4GB on DRA7x TI platform.

p = 0kB [ 66.962769] Total swap = 0kB [ 66.965069] 1042176 pages RAM [ 66.967429] 837376 pages HighMem/MovableOnly [ 66.969836] 37773 pages reserved [ 66.971648] 49152 pages cma reserved Regards, Priyaranjan ___ Kernelnewbies mail

DMA engine doesn't allow callbacks in Interrupt context.

n my audio driver such that all intermediate callbacks are necessary to handle as they get involve in updating other Data structures and triggering other DMAs. Please help me to understand this. Regards, Priyaranjan ___ Kernelnewbies mailing list Ker

Re: Understanding Platform devices and platform drivers.

Hi Madhu, >On Mon, Nov 7, 2016 at 12:43 PM, Madhu K wrote: >Hi All, >I am trying to understand the concept of platform device and platform driver, >my very basic question is that, the devices and > data which is present in >device tree represents platform devices and platform data The device

Re: ARM Linux: Where the SDRAM address and size defined

Hello Woody, >On Mon, Mar 7, 2016 at 10:55 AM, Woody Wu wrote: > >Hi, > > >In Samsung s3c24xx arch code, I cannot find where the SDRAM address and > size information was defined. Can someone give me a lead? Thanks. > > I will try to answer this. Its usual practice to have the size of RAM in boo

Re: Mutex and Spinlock locked together

a mutex. e.g. mutex_lock--->spinlock-critical section-spinunlock--->mutex_unlock. >* You can not take a mutex under a spinlock. e.g. spinlock--->mutex_lock -critical section mutex_unlock>spinunlock is not allowed. On Thu, Feb 25, 2016 at 11:37 AM, priyaranjan wro

Mutex and Spinlock locked together

Hello All, Do you have any idea of a situation where we would need mutex and spinlock to be locked together? I think there is an example for this in Linux kernel. Can anyone help me? Regards, Priyaranjan ___ Kernelnewbies mailing list Kernelnewbies

Does Linux kernel disables any Interrupts while going into IRQ handler?

ed and is masked in the flow handler when an interrupt event happens*. This prevents losing edge interrupts on hardware which does not store an edge interrupt event while the interrupt is disabled at the hardware level. Can anyone please explain the bold line here? Regards, Pr

Re: How to handle float-point operations

Hello Arun, On Wed, Jul 8, 2015 at 1:26 PM, Arun KS wrote: > Hello Priyaranjan, > > On Mon, Jul 6, 2015 at 1:13 PM, priyaranjan > wrote: >> On Wed, Jul 01, 2015 at 01:58:30PM +0530, priyaranjan wrote: >>> Hi Arun, >>> >>> >>> >On

Re: How to handle float-point operations

On Wed, Jul 01, 2015 at 01:58:30PM +0530, priyaranjan wrote: > Hi Arun, > > > >On Thu, Jun 25, 2015 at 2:33 PM, Arun KS wrote: > >Hello Mudongliang, > > > > > > >On Tue, Jun 23, 2015 at 9:01 AM, 慕冬亮 wrote: > > >> > > >> I

Re: How to handle float-point operations

Hi Arun, >On Thu, Jun 25, 2015 at 2:33 PM, Arun KS wrote: >Hello Mudongliang, > > > >On Tue, Jun 23, 2015 at 9:01 AM, 慕冬亮 wrote: > >> > >> I know there are rarely float-point operations! What's the exception? > > In the linux kernel, how does it handle the float-point operations in > the >userl

Re: Delivery Status Notification (Failure)

>On Thu, Aug 7, 2014 at 12:59 AM, wrote: > >On Wed, 06 Aug 2014 15:07:21 -0400, Nick Krause said: > >> Does anybody have some work in the scheduler subsystem I can work on > >> that is a good top dipping for a kernel newbie. > > I think you should start with learning the schedular and it code...

Disabling a BH : spin_lock_bh or local_bh_disable.

anybody can help me understand what happens when a BH is disabled with Interrupts still enabled for the BH. Regards, Priyaranjan ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: SOC: Zedboard: Driver question

On Thu, Jun 12, 2014 at 8:13 PM, amit mehta wrote: > On Thu, Jun 12, 2014 at 4:52 PM, priyaranjan > wrote: > > > > > > > > On Thu, Jun 12, 2014 at 7:09 PM, amit mehta > wrote: > >> > >> We are working on a school project in which we are tr

Re: SOC: Zedboard: Driver question

On Thu, Jun 12, 2014 at 7:09 PM, amit mehta wrote: > We are working on a school project in which we are trying to develop a > audio mixer > on Zedboard (Development board from Digilent). We have developed the IP > and have > integrated it with the overall hardware using Programmable logic. This >

Re: Booting Custom Kernel

Dipanjan, I hope the steps remains same even though if we have an windows OS in the same machine. Please confirm. Regards. Priyaranjan On Mon, Jun 9, 2014 at 9:23 AM, Dipanjan Das wrote: > > Dear Arindam, > > What I understand is, your system has two Ubuntu 12.04 installations si

Linux MM : virtual memory address space

t about 64-bit system? Where does the code lie in linux kernel for the check? Is there any latest and updated memory management documentation for Linux kernel? Regards, Priyaranjan ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbie

Re: Reset due to emergency remount r/o

On Mon, Mar 3, 2014 at 3:22 PM, Vignesh Radhakrishnan wrote: > Probably , adb reboot bootlooader command from the host to which the > device is connected. > PD : No, that command wasn't executed from the host. > > Thanks and regards, > Vignesh Radhakrishnan > > > On Sat, Mar 1, 2014 at 9:56 AM

Reset due to emergency remount r/o

wapper/0(0) [ 426.187430,0] Going down for restart now Regards, Priyaranjan ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Re: Kernel Development

On Sun, Feb 23, 2014 at 10:54 PM, subham soni wrote: > Hello, > I am a newbie to kernel development. I would like to develop my own > kernel from scratch. From where should I start from? I have a good > experience of the commands in Linux (Ubuntu,Fedora,Debian,Slackware). You can start wi

Interrupts : request_percpu_irq function

this has been extensively used in architecture specific files especially the timers and the watchdog. Also it would be great, if someone can point out any document/link where I can find the description. I failed to find it from Linux kernel documentation. Regards, Priyar