Re: Delegating printk work to UART interrupt

2015-07-22 Thread Arun KS
Hello Alexander, On Wed, Jul 22, 2015 at 11:08 AM, Alexander alexhoppus...@gmail.com wrote: Hi Arun KS, Actually, i already saw this one and something similar were tested. I just trying to figure out the reasons why generic kernel layer (console_unlock) implemented in such way: i.e. why

Re: Delegating printk work to UART interrupt

2015-07-19 Thread Arun KS
Hello Alexander, On Sat, Jul 18, 2015 at 11:23 AM, Alexander alexhoppus...@gmail.com wrote: Hi! When i checked how kernel printing works, i mentioned that it takes messages from log_buffer in console_unlock and gives it to call_console_drivers - ... - some uart bsp function. Basically, as

Re: How to handle float-point operations

2015-07-08 Thread Arun KS
Hello Priyaranjan, On Mon, Jul 6, 2015 at 1:13 PM, priyaranjan priyaranjan45...@gmail.com wrote: 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 getaru...@gmail.com wrote: Hello Mudongliang, On Tue, Jun 23, 2015 at 9:01 AM

Re: How to handle float-point operations

2015-06-25 Thread Arun KS
Hello Mudongliang, On Tue, Jun 23, 2015 at 9:01 AM, 慕冬亮 mudonglianga...@gmail.com 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 userland? Most of the userspace programs do not use FP

Re: Kernel booting stuck at CPU1: Booted secondary processor

2015-03-17 Thread Arun KS
Hello Ayan, On Tue, Mar 17, 2015 at 11:44 AM, AYAN KUMAR HALDER ayankum...@gmail.com wrote: Hi, I am porting kernel (3.14.22) on a custom ARM(Cortex A9 x 3) based platform. I was able to get it working on uniprocessor mode. Now I wish to get the SMP mode working as mine is Cortex A9 x3

Re: Understanding the mapping of physical memory to kernel address space

2015-03-15 Thread Arun KS
. I also read on a stack overflow thread that LOW_MEM is memory that is permanently mapped into KVA, while HIGH_MEM is mapped as required. Is this true? Absolutely Thanks, Arun Thanks, Sunny On Sun, Mar 15, 2015 at 1:17 PM, Arun KS getaru...@gmail.com wrote: Hello Sunny, On Sat, Mar 14

Re: Understanding the mapping of physical memory to kernel address space

2015-03-15 Thread Arun KS
: -Original Message- From: kernelnewbies-boun...@kernelnewbies.org [mailto:kernelnewbies-boun...@kernelnewbies.org] On Behalf Of Arun KS Sent: Thursday, March 12, 2015 11:03 AM To: Sunny Shah Cc: kernelnewbies Subject: Re: Understanding the mapping of physical memory to kernel address space

Re: Understanding the mapping of physical memory to kernel address space

2015-03-12 Thread Arun KS
Hello Sunny, On Thu, Mar 12, 2015 at 10:32 PM, Sunny Shah shahsunny...@gmail.com wrote: Hello, This is my first mail on this list, so please let me know if I'm erring. I'm reading Bovet and Cesati's Understanding the Linux Kernel, specifically the chapter Memory Addressing, sub-section

Re: How to generate a kernel source tree with macros expanded?

2015-03-09 Thread Arun KS
Hi Tao, On Mon, Mar 9, 2015 at 10:38 AM, Tao Jiang (姜涛) jiangtao@gmail.com wrote: Hi: After make menuconfig, is there a way to generate a kernel source tree with macros expanded? It's too complicate for me to find out wether a macro is defined or not, or which value is used for a macro.

Re: ACCESS_ONCE usage inside llist_add_batch function

2015-03-04 Thread Arun KS
Hi Akturk, On Sun, Mar 1, 2015 at 1:42 AM, Cihangir Akturk cakt...@gmail.com wrote: Reading the lib/llist.c file in the kernel sources, I came across the llist_add_bach function defined like this; bool llist_add_batch(struct llist_node *new_first, struct llist_node *new_last,

Re: workqueues - how to use them correctly

2015-02-11 Thread Arun KS
Hello Roshan, On Tue, Feb 10, 2015 at 2:20 PM, Roshan A roshan@gmail.com wrote: hi all, My question is regarding the correct use of workqueues. I have a driver which queues a work item in the interrupt handler. The bottom half function ( the workitem -function ) does have proper locking

Re: spinlock variable protection

2015-01-30 Thread Arun KS
Hi, On Fri, Jan 30, 2015 at 8:53 PM, Malte Vesper malte.ves...@postgrad.manchester.ac.uk wrote: Spinlocks imply memory barriers as far as I am aware... Read here: http://lxr.free-electrons.com/source/Documentation/memory-barriers.txt#L1634 And may be here aswell,

Re: Ticketing spinlocks - How to get to the owner who locked the spinlock?

2015-01-26 Thread Arun KS
, Jan 27, 2015 at 3:12 PM, Arun KS getaru...@gmail.com wrote: Hello Manty, On Tue, Jan 27, 2015 at 11:27 AM, manty kuma mantyk...@gmail.com wrote: Hi All, Currently I am looking into an issue which is holding the printk lock(logbuf_lock) logbuf_lock = { raw_lock = { owner

Re: Ticketing spinlocks - How to get to the owner who locked the spinlock?

2015-01-26 Thread Arun KS
Hello Manty, On Tue, Jan 27, 2015 at 11:27 AM, manty kuma mantyk...@gmail.com wrote: Hi All, Currently I am looking into an issue which is holding the printk lock(logbuf_lock) logbuf_lock = { raw_lock = { owner = 0, next = 4 } } I read about ticketing spinlocks to

Re: Re: work queue

2014-11-25 Thread Arun KS
Hello Jay, On Thu, Nov 20, 2014 at 7:06 PM, 户户 6563...@163.com wrote: Thank you for reply, Isn't this function 'create_workqueue(myfoo);' gonna create a new worker? create_workqueue will not create a new worker. Workers are created and destroyed dynamically, and is independent of the

Re: understanding cpuidle

2014-10-21 Thread Arun KS
Hi Ran, On Thu, Oct 16, 2014 at 1:12 PM, Ran Shalit ransha...@gmail.com wrote: Hello, I try to understand the cpuidle main concept but have some difficulties. I could not find any documentation to explain the cpuidle. what does it mean that it enters idle when no thread to run ?if I have

Re: confused kernel compressed code link address

2014-05-12 Thread Arun KS
Hi Chuck Huang, On Thu, May 8, 2014 at 5:25 PM, Chuck Huang chuck.ker...@gmail.com wrote: Dear all, Now i am looking into kernel decompressed code, arch/arm/boot/compressed/head.S As i objdump arch/arm/boot/compressed/vmlinux, the start section address is 0x0. vmlinux.S 373789|

Re: loglevel 7 (debug) and pr_debug()

2014-04-16 Thread Arun KS
Hi Martin, On Wed, Apr 16, 2014 at 2:13 PM, Martin Kepplinger mart...@posteo.de wrote: I'm on Debian here and I don't really get pr_debug and printk(KERN_DEBUG ...). Let's stick to pr_debug. I have DYNAMIC_DEBUG enabled and root@laptop:/proc/sys/kernel# cat /proc/sys/kernel/printk 7 7

Re: loglevel 7 (debug) and pr_debug()

2014-04-16 Thread Arun KS
Hi Martin, On Wed, Apr 16, 2014 at 2:46 PM, Martin Kepplinger mart...@posteo.de wrote: Am 2014-04-16 11:00, schrieb Arun KS: Hi Martin, On Wed, Apr 16, 2014 at 2:13 PM, Martin Kepplinger mart...@posteo.de wrote: I'm on Debian here and I don't really get pr_debug and printk(KERN_DEBUG

Re: loglevel 7 (debug) and pr_debug()

2014-04-16 Thread Arun KS
16, 2014 at 1:11 PM, Martin Kepplinger mart...@posteo.de wrote: Am 16.04.2014 11:58 schrieb Arun KS: Hi Martin, On Wed, Apr 16, 2014 at 2:46 PM, Martin Kepplinger mart...@posteo.de wrote: Am 2014-04-16 11:00, schrieb Arun KS: Hi Martin, On Wed, Apr 16, 2014 at 2:13 PM

Re: flush_dcache_page from user space.

2014-04-01 Thread Arun KS
Hi Ratheesh, On Tue, Apr 1, 2014 at 11:54 AM, ratheesh kannoth ratheesh@gmail.com wrote: On Tue, Apr 1, 2014 at 11:50 AM, Arun KS getaru...@gmail.com wrote: This requirement depends on what cache your hardware has. Can you give more details about your processor? If you have VIPT non

Re: Unable to handle kernel paging request at virtual address ... while writing to frame buffer..

2014-03-27 Thread Arun KS
Hi Chan, On Thu, Mar 27, 2014 at 2:25 PM, Chan Kim c...@etri.re.kr wrote: Hi, I have this 'unable to handle kernel paging request at virtual address ...' This means the virtual address used doesn't have a proper mapping in the page table. Thanks, Arun when writing to the frame buffer. Has

Re: How Kernel stack is used in case of different processor mode in ARM architecture?

2014-03-25 Thread Arun KS
Hello Rahul, On Tue, Mar 25, 2014 at 6:29 AM, Rahul Garg rahul.lnm...@gmail.com wrote: As I understand every process have a user stack and kernel stack. True. Apart from that there is a stack for every mode in ARM achitecture. So This is wrong. Only irq, abort and undefined modes have stacks

Re: How Kernel stack is used in case of different processor mode in ARM architecture?

2014-03-25 Thread Arun KS
On Tue, Mar 25, 2014 at 2:58 PM, Arun KS getaru...@gmail.com wrote: Hello Rahul, On Tue, Mar 25, 2014 at 6:29 AM, Rahul Garg rahul.lnm...@gmail.com wrote: As I understand every process have a user stack and kernel stack. True. Apart from that there is a stack for every mode in ARM

Re: Vmalloc Information Needed

2014-03-25 Thread Arun KS
Hello Anup, On Sun, Mar 23, 2014 at 9:54 AM, Anup Buchke anup.est...@gmail.com wrote: For a user/kernel configuration of 3/1GB and (0-16M DMA , 16-896 - Low , 896 - 1024 - High ) Q: Is amount of memory allocated to Vmalloc limited to 128MB? No. 128MB is the default vmalloc size. You can

Re: How Kernel stack is used in case of different processor mode in ARM architecture?

2014-03-25 Thread Arun KS
On Tue, Mar 25, 2014 at 4:40 PM, Arun KS getaru...@gmail.com wrote: Hello Rahul, On Tue, Mar 25, 2014 at 4:10 PM, Rahul Garg rahul.lnm...@gmail.com wrote: Hi Arun, Lines from Robert Love : Early in the 2.6 kernel process, an option was added to reduce the stack size from two pages down

Re: How Kernel stack is used in case of different processor mode in ARM architecture?

2014-03-25 Thread Arun KS
, Arun KS getaru...@gmail.com wrote: On Tue, Mar 25, 2014 at 2:58 PM, Arun KS getaru...@gmail.com wrote: Hello Rahul, On Tue, Mar 25, 2014 at 6:29 AM, Rahul Garg rahul.lnm...@gmail.com wrote: As I understand every process have a user stack and kernel stack. True. Apart from that there is a stack

Re: How Kernel stack is used in case of different processor mode in ARM architecture?

2014-03-25 Thread Arun KS
, Arun KS getaru...@gmail.com wrote: On Tue, Mar 25, 2014 at 4:40 PM, Arun KS getaru...@gmail.com wrote: Hello Rahul, On Tue, Mar 25, 2014 at 4:10 PM, Rahul Garg rahul.lnm...@gmail.com wrote: Hi Arun, Lines from Robert Love : Early in the 2.6 kernel process, an option was added to reduce

Re: Vmalloc Information Needed

2014-03-25 Thread Arun KS
Hi Pramod, On Tue, Mar 25, 2014 at 5:08 PM, pramod gurav pramod.gurav@gmail.com wrote: Hi Arun, On Tue, Mar 25, 2014 at 3:55 PM, Arun KS getaru...@gmail.com wrote: Hello Anup, On Sun, Mar 23, 2014 at 9:54 AM, Anup Buchke anup.est...@gmail.com wrote: For a user/kernel configuration

Re: Reset due to emergency remount r/o

2014-02-26 Thread Arun KS
Hi Priyaranjan, On Wed, Feb 19, 2014 at 6:14 PM, Priyaranjan Das priyaranjan456...@gmail.com wrote: Hi All, I am facing an kernel restart due to emergency remount. Could anybody tell me general techniques to go head with the debugging? Below are the logs which are seen during a reboot.

Re: Firmware Loading every boot?

2014-02-10 Thread Arun KS
Hi Jeshwanth, On Mon, Feb 10, 2014 at 6:59 PM, Jeshwanth jeshkumar...@gmail.com wrote: Hello List, I came to know that, linux loads firmware for my dma everytime it boots. But I don't understand, why it is required to load everytime it boots, don't dma holds which is loaded previously.

Re: Firmware Loading every boot?

2014-02-10 Thread Arun KS
. HTH. Thanks, Arun Please let me know whether my assumption is right :) On Mon, Feb 10, 2014 at 7:27 PM, Arun KS getaru...@gmail.com wrote: Hi Jeshwanth, On Mon, Feb 10, 2014 at 6:59 PM, Jeshwanth jeshkumar...@gmail.comwrote: Hello List, I came to know that, linux loads firmware

Re: How to allocate memory and get the physical address in kernel

2014-02-06 Thread Arun KS
Hi Silverstri, On Thu, Feb 6, 2014 at 7:56 AM, m silverstri michael.j.silvers...@gmail.com wrote: Hi, I am developing a kernel driver. I need to allocate buffer in the kernel driver and pass the physical address of the buffer to the Chip register so that it can generate output there. I

Re: Flush cache for memory allocated by kmalloc

2014-02-06 Thread Arun KS
Hi Silverstri, On Fri, Feb 7, 2014 at 12:54 AM, m silverstri michael.j.silvers...@gmail.com wrote: Hi, I allocate memory in my driver and I passed this address to my HW register to write to. My question is when the HW done writing (my driver get notified by an interrupt). How can I flush

Re: QorIQ P1020 dual core - driver initialization duplication

2014-02-06 Thread Arun KS
Hi Maxime, On Thu, Feb 6, 2014 at 9:23 PM, Maxime Moge maxime.m...@sick.de wrote: Hi guys, I m struggling to get rid of double kernel log while the kernel is booting. Here a part of the kernel messages: *WARNING: adjusting available memory to 3000* *## Booting kernel from Legacy

Re: Question about using spinlock to synchronize between kernel driver and an interrupt handler

2014-02-03 Thread Arun KS
Hi Silverstri, On Sun, Feb 2, 2014 at 1:19 PM, m silverstri michael.j.silvers...@gmail.com wrote: On Sat, Feb 1, 2014 at 5:34 AM, Josh Cartwright jo...@eso.teric.us wrote: On Sat, Feb 01, 2014 at 01:32:49AM -0800, anish singh wrote: On Sat, Feb 1, 2014 at 1:15 AM, m silverstri

Re: Recovering Linux system from hung state via software

2013-12-04 Thread Arun KS
Hi Vipul, On Fri, Nov 29, 2013 at 5:58 AM, Vipul Jain vipu...@gmail.com wrote: Hi Kernel alias, I am a newbie and I am trying to figure out ways where in I can recover the Linux in below two scenarios: 1. my specific process hangs. 2. kernel gets hung partially or completely. I have done

Re: Ordering / preemption of work in a workqueue preempt?

2013-11-18 Thread Arun KS
Hi Rajat, On Fri, Nov 15, 2013 at 8:46 PM, Rajat Jain rajatj...@juniper.net wrote: Hi, I have a single work queue, on which I have scheduled a worker function [using queue_work(wq, fn)] in interrupt context. I get the interrupt twice before the work queue gets a chance to run, and hence

Re: Address Types in Linux

2013-11-05 Thread Arun KS
Hi Anup, I ll give a try. On Sat, Nov 2, 2013 at 5:14 AM, Anup Buchke anup.est...@gmail.com wrote: Hi all, I am studying LDD3. It mentions the following types of address which is creating some confusion. User Virtual Address : The address space of a process. This ranges from 0-3Gb for

Re: Mapping of ZONE_HIGHMEM in kernel address space in 32bit x86

2013-05-14 Thread Arun KS
Hi Sergio, On Tue, May 14, 2013 at 12:41 AM, Sergio Andrés Gómez del Real sergio.g.delr...@gmail.com wrote: I've got some questions regarding this linear to physical address mapping on x86 architecture; I'm not sure I've grassped the whole thing. Before asking, I'd like to be sure I

Re: Do we use ARM's system mode in linux kernel

2013-04-29 Thread Arun KS
Hi Dhiraj, On Fri, Apr 26, 2013 at 12:58 PM, Dhiraj Kumar dhl...@gmail.com wrote: Hi All, ARM is running in Supervisor(SVC) Mode in kernel. ARM also has another mode called System(SYS) Mode. I just needed info if linux kernel uses system mode of ARM processor. Please share information if

Re: Using vmalloc in device driver code

2013-04-05 Thread Arun KS
Hi Neha, On Fri, Apr 5, 2013 at 12:25 AM, neha naik nehanai...@gmail.com wrote: Hi All, From what i have learnt vmalloc requires a minor page fault to sync the process page tables with the reference page tables. So, is it safe to use memory already allocated by vmalloc in io context/device

Re: Need of different memory zones

2013-03-15 Thread Arun KS
Hi Niroj, On Wed, Mar 13, 2013 at 3:16 PM, Niroj Pokhrel nirojpokh...@gmail.com wrote: Hi All, I have been studying Memory Management in linux. But I am confused with the division of different ZONE. The use of ZONE_DMA and ZONE_NORMAL is fine. But I am confused with ZONE_HIGHMEM, if the

Re: Need of different memory zones

2013-03-15 Thread Arun KS
Hi Niroj, On Fri, Mar 15, 2013 at 2:39 PM, Niroj Pokhrel nirojpokh...@gmail.com wrote: On Fri, Mar 15, 2013 at 12:31 PM, Arun KS getaru...@gmail.com wrote: Hi Niroj, On Wed, Mar 13, 2013 at 3:16 PM, Niroj Pokhrel nirojpokh...@gmail.com wrote: Hi All, I have been studying Memory

Re: How to measure the RAM read/write performance

2013-03-04 Thread Arun KS
Thanks Sandeep On Mon, Mar 4, 2013 at 12:15 PM, Arun KS getaru...@gmail.com wrote: Hi Sandeep, On Sat, Mar 2, 2013 at 12:21 PM, sandeep kumar coolsandyfor...@gmail.com wrote: Another easy way to make memory(ie..pages) non cacheble is use the below function, dma_alloc_coherent(NULL

Re: How to measure the RAM read/write performance

2013-03-03 Thread Arun KS
have one doubt in how to do DMA? Can you give me some example driver code, for this following case -- I want to do a DMA from a mem mapped I/O (lets say physical 0x4000) to RAM location @ 0x8000. How do you do this? Thanks Sandeep On Fri, Mar 1, 2013 at 10:45 AM, Arun KS

Re: How to measure the RAM read/write performance

2013-02-28 Thread Arun KS
On Tue, Feb 26, 2013 at 6:50 PM, ankur dwivedi ankurengg2...@gmail.com wrote: I am not sure but what if you make the variable as a volatile? Volatile in simple terms == Consider this eg: 1 int main(void){ 2 int a, x, y; 3 x=a; 4 y=a; 5 } Line 3 with be converted to a LDR

Re: relocatable modules' symbols

2013-02-28 Thread Arun KS
Hi Horseriver, On Sun, Feb 24, 2013 at 7:26 AM, horseriver horseriv...@gmail.com wrote: On Sun, Feb 24, 2013 at 04:00:37PM +0700, Mulyadi Santosa wrote: On Sat, Feb 23, 2013 at 6:45 AM, horseriver horseriv...@gmail.com wrote: hi: I have built vmlinux at the top dir of kernel source

Re: atomic operations

2013-02-28 Thread Arun KS
Hi Peter, On Sun, Feb 24, 2013 at 6:20 PM, Peter Teoh htmldevelo...@gmail.com wrote: in simple terms, any operation, in terms assembly instructions, which can be executed in ONE instruction, is atomic, because, just like an atom, it cannot be broken up into parts. any instructions that is

Re: Examples of Per-CPU Variables in Kernel source

2013-02-28 Thread Arun KS
On Sun, Feb 24, 2013 at 2:07 PM, Shraddha Kamat sh200...@gmail.com wrote: I was reading about Per-CPU Variables from UTLK. Where are such variables used in the kernel source code - example. Use grep utility to find it out . Thanks, Arun -- Shraddha

Re: how to look for source code in kernel

2012-12-28 Thread Arun KS
On Fri, Dec 28, 2012 at 3:19 PM, Mulyadi Santosa mulyadi.sant...@gmail.comwrote: On Fri, Dec 28, 2012 at 12:19 PM, anish singh anish198519851...@gmail.com wrote: On Fri, Dec 28, 2012 at 10:42 AM, amit mehta gmate.a...@gmail.com wrote: On Thu, Dec 27, 2012 at 11:01:52PM +0530, kishore kumar

Re: Interrupt handling - Linux

2012-11-29 Thread Arun KS
Hello Manty, On Wed, Nov 28, 2012 at 8:10 PM, manty kuma mantyk...@gmail.com wrote: In linux interrupt programming, we do request_irq(...) in this function, the first argument is irq number. If i am not wrong, this is the interrupt line that we are requesting from kernel. For one particular

Re: Finding the interrupt vector of a given IRQ

2012-10-20 Thread Arun KS
Hi Anish, On Sat, Oct 20, 2012 at 9:38 AM, anish kumar anish198519851...@gmail.comwrote: On Fri, 2012-10-19 at 10:34 +0530, Arun KS wrote: Hi Anish, On Mon, May 28, 2012 at 9:16 AM, anish singh anish198519851...@gmail.com wrote: On Mon, May 28, 2012 at 2:57 AM, richard -rw

Re: What rationale behind physical and virtual kernel memory layout ?

2012-10-19 Thread Arun KS
Hi Telenn, On Fri, Oct 19, 2012 at 3:03 PM, telenn barz telenn.b...@gmail.com wrote: Hi all, This a vast topic. But I believe it's worthwhile exposing in greater detail the Why this design has been chosen ?, before the How this design has been implemented ?. And I think this is a common

Re: where are the bug ?

2012-10-19 Thread Arun KS
Hi Fan, On Fri, Oct 19, 2012 at 6:50 PM, Fan Yang lljyang...@gmail.com wrote: HI ALL: I just run a module on my machine, but it can't work. When the module run the kernel will painc. I don't know where is wrong. This is my code: 1 #includelinux/module.h 2 #includelinux/kernel.h

Re: Finding the interrupt vector of a given IRQ

2012-10-18 Thread Arun KS
Hi Anish, On Mon, May 28, 2012 at 9:16 AM, anish singh anish198519851...@gmail.comwrote: On Mon, May 28, 2012 at 2:57 AM, richard -rw- weinberger richard.weinber...@gmail.com wrote: On Sun, May 27, 2012 at 2:02 AM, Mark Farnell mark.farn...@gmail.com wrote: In the kernel, how can I find

Re: kernel stack memory

2012-09-13 Thread Arun KS
Hello Shubham, On Thu, Sep 13, 2012 at 12:15 PM, shubham sharma shubham20...@gmail.comwrote: Hi, As far as i know, the size of stack allocated in the kernel space is 8Kb for each process. But in case i use more than 8Kb of memory from the stack then what will happen? I think that in that

Re: Difference between kernel 3.0.15 and kernel 3.4

2012-09-03 Thread Arun KS
Hello Ritesh, On Fri, Aug 31, 2012 at 4:39 PM, Ritesh Harjani ritesh.harj...@gmail.comwrote: Hey just an update, kernel 3.0.15 of Android-ICS and 3.4 of Android-JB. Sorry if i am wrong anywhere.. I am new to this :). Here you go, http://kernelnewbies.org/Linux_3.4 Thanks, Arun Thank

Re: Changing the page attributes

2012-07-11 Thread Arun KS
On Wed, Jul 11, 2012 at 12:04 PM, Arun KS getaru...@gmail.com wrote: Hello Mulyadi, On Tue, Jul 10, 2012 at 9:42 PM, Mulyadi Santosa mulyadi.sant...@gmail.com wrote: Hi.. On Tue, Jul 10, 2012 at 6:51 PM, Arun KS getaru...@gmail.com wrote: Hello Experts, I have a requirement to change

Re: Kernel Memory

2012-06-21 Thread Arun KS
Hello Vijay, On Thu, Jun 21, 2012 at 5:57 PM, Vijay Chauhan kernel.vi...@gmail.com wrote: Hello, I am newbie. It has been said kernel memory is not pageable What does it mean? There is no concept of kernel virtual address? You might have heard about 3G/1G split. This 1GB is the virtual

Re: Continuous Interrupt Problem

2012-06-14 Thread Arun KS
Hello Siddharth, On Thu, Jun 14, 2012 at 10:34 AM, siddharth saxena siddharthsaxena1...@gmail.com wrote: Hi all I need help with an issue. I have written a touch driver for a device and used the flag IRQF_TRIGGER_LOW to request irq. Now, when I boot the device, the touch interrupts are

Re: Continuous Interrupt Problem

2012-06-14 Thread Arun KS
On Thu, Jun 14, 2012 at 12:21 PM, Sarbojit Ganguly unixman.linux...@gmail.com wrote: Hi Arun, While I agree to your pointers but he is facing the problem of interrupt floods even before he touches. IMHO the culprit could be the flag. On 14 June 2012 12:01, Arun KS getaru...@gmail.com

Re: Compile the pwm driver

2012-06-07 Thread Arun KS
Hello Jeshwanth, On Fri, Jun 8, 2012 at 8:31 AM, jeshwanth Kumar N K jeshkumar...@gmail.com wrote: Hello all Accidenteally my sys interface for pwm got deleted in beaglebone. Now I have got the source code, it contains kconfig, make file and source code. Please help me to compile and install

Re: cache policy of arm mmu

2012-05-29 Thread Arun KS
Hello Jacky, On Tue, May 29, 2012 at 10:09 AM, h.t.ja...@gmail.com h.t.ja...@gmail.com wrote: Hi Cunsuo, Thanks for you prompt reply. But I'm just wondering why the other policies(such as writethrough) are abandoned, does anyone know the architecture difference? They are not abandoned from

Re: Writing a single buffer in kernel ring buffer take 6-8 ms

2012-05-03 Thread Arun KS
Hi Chetan, On Thu, May 3, 2012 at 3:35 PM, Chetan Nanda chetanna...@gmail.com wrote: Hi, We are working on ARM based SOC. Currently we are implementing a efficient tracing mechanism to logs messages from a dedicated MCU. For this, we share a circular buffer between ARM and MCU and messages

Re: side effects of calling interruptible_sleep_on_timeout()

2012-04-26 Thread Arun KS
back before we really schedules out. So this problem won't occur in our Linux kernel. Thanks, Arun Regards Shashidhara -Original Message- From: Arun KS [mailto:getaru...@gmail.com] Sent: Thursday, April 26, 2012 11:36 AM To: Shashidhara Shamaiah Subject: Re: side effects of calling

Re: Kernelnewbies Digest, Vol 17, Issue 44

2012-04-26 Thread Arun KS
Hi Jeshwanth, On Thu, Apr 26, 2012 at 11:10 PM, Jeshwanth Kumar N K Jeshu jeshkumar...@gmail.com wrote: Hello guys, I am writing a user space code for pwm controller in beaglebone, but the drivers are in the form of files, so when I am writing the code I got a doubt that, if we keep access

Re: stdout to console

2012-04-25 Thread Arun KS
and /dev/pts/* device files. Plz have a look here, http://linux.die.net/man/4/pts Arun --Sri. On Mon, Apr 23, 2012 at 6:15 AM, Arun KS getaru...@gmail.com wrote: Hello Guys, We all know that when an application writes to stdout, data ends up in the console. Okey so if I m on my

Re: side effects of calling interruptible_sleep_on_timeout()

2012-04-25 Thread Arun KS
Hi Srivatsa, On Wed, Apr 25, 2012 at 3:56 PM, Srivatsa S. Bhat srivatsa.b...@linux.vnet.ibm.com wrote: On 04/25/2012 03:36 AM, Philipp Ittershagen wrote: Hi Devendra, On Tue, Apr 24, 2012 at 03:24:23PM +0530, devendra rawat wrote:    Hi,    A switch driver is causing soft lockup on

stdout to console

2012-04-23 Thread Arun KS
Hello Guys, We all know that when an application writes to stdout, data ends up in the console. Okey so if I m on my development board and if I run an app, all the prints comes to the console (eg /dev/ttyS0). If I m on any server using ssh and all apps prints comes on my putty (eg through

Write-up on a I2C driver issue

2012-04-23 Thread Arun KS
Hello Everyone, I have a short wirte up on I2C driver. For the newbiews it will give lot of information. For the experienced, if time permits, please read and point out my mistakes. Here come the link, http://www.hackers4hackers.blogspot.in/2012/03/real-life-picture-of-i2c.html Thanks, Arun

Re: About module priority

2012-04-19 Thread Arun KS
Hi Geraint, On Thu, Apr 19, 2012 at 2:05 PM, Geraint Yang geraint0...@gmail.com wrote: Hi folks, I am writing a kernel module for a sd card, but when I insert a sd card into my box, the default sd driver will probe before my driver, and my driver will never have chance to probe. Is there any

BUG: scheduling while atomic

2012-04-18 Thread Arun KS
Hello Guys, System is working normal after this BUG. PC is at 0x400b4614, probably a mmaped address. Just wondering how can this BUG happen when a process is running in user space. Can it be something like this 1) enter to kernel from userspace through some system call. 2) kernel disables the

Re: BUG: scheduling while atomic

2012-04-18 Thread Arun KS
Hi Dave, Thanks for your reply. On Wed, Apr 18, 2012 at 1:01 PM, Dave Hylands dhyla...@gmail.com wrote: Hi Arun, On Tue, Apr 17, 2012 at 11:44 PM, Arun KS getaru...@gmail.com wrote: Hello Guys, System is working normal after this BUG. PC is at 0x400b4614, probably a mmaped address

Re: BUG: scheduling while atomic

2012-04-18 Thread Arun KS
Hi Srivatsa, On Wed, Apr 18, 2012 at 1:57 PM, Srivatsa S. Bhat srivatsa.b...@linux.vnet.ibm.com wrote: On 04/18/2012 01:38 PM, Arun KS wrote: Hi Dave, Thanks for your reply. On Wed, Apr 18, 2012 at 1:01 PM, Dave Hylands dhyla...@gmail.com mailto:dhyla...@gmail.com wrote

Re: BUG: scheduling while atomic

2012-04-18 Thread Arun KS
On Wed, Apr 18, 2012 at 12:14 PM, Arun KS getaru...@gmail.com wrote: Hello Guys, System is working normal after this BUG. PC is at 0x400b4614, probably a mmaped address. Just wondering how can this BUG happen when a process is running in user space. Can it be something like this 1

Re: problem mapping physical address from /dev/mem

2011-10-07 Thread Arun KS
On Thu, Oct 6, 2011 at 1:04 AM, Vaibhav Jain vjoss...@gmail.com wrote: Hi, I am trying to run a program that scans memory from a given physical address using /dev/mem. It uses mmap to map physical address from /dev/mem. So to start with I used /proc/iomem to look up the physical memory