May 2013 - kernelnewbies@kernelnewbies.org - Kernelnewbies Mailing Lists

Re: [I2C] informations + advice about messages handling
by Mylene Josserand May 29, 2013

May 29, 2013

Hi Jean, Le 24/05/2013 14:20, Jean Delvare a écrit : > On Fri, 24 May 2013 11:52:54 +0200, Mylene Josserand wrote: >> - an audio codec tlv320aic3204 : There is a driver for this device but >> for some reasons, we did not use it. Did not find a "SMBus compliant" in >> its datasheet. > > The tlv320aic32x4 driver uses i2c_master_send, which is a shortcut to > i2c_transfer. However it seems to only send 2 bytes on the bus at once, > the same could be achieved with i2c_smbus_write_byte_data if needed. Okay, thanks to have looked at it ! > > For completeness: a device might use transactions which are compliant > with SMBus without being formally "SMBus-compliant", because SMBus has > more constraints than just transaction types (I kept things simple > originally to not confuse you.) This may explain why it isn't mentioned > in the datasheet. Or just because the manufacturer did not care because > they target fully I2C-capable systems anyway. > > What you have to look at is the transaction types. They are usually > described in the datasheet. Then compare with either the SMBus > specification or > http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documen… > and if they match then you can use the i2c_smbus_*() calls. I have checked the PIC18F24201 according to your advice and, of what I have seen, it can handle the SMBus protocol. Thank you for the explanation and trying to keep it simple for me :) -- Mylène JOSSERAND

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c library wrapper function
by Varun Sharma May 28, 2013

May 28, 2013

Hi, I am tracing send system call . before going to kernel space system call no. conversion happens in c library wrapper function.how to get the name of that library which hold wrapper function of send system call

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about ssh
by Varun Sharma May 28, 2013

May 28, 2013

Hi, I want to know how two independent ssh session use same port for communication .At what level difference is come.

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Kernel 64bit
by Giridhara RP (grp) May 28, 2013

May 28, 2013

Hi, I am trying to build 64bit kernel (linux kernel 2.6.32-60). But, once I boot the image (ISO), uname -a still shows as i686. It does not show as 'X86_64'. My vmlinuz and vmlinuz.o shows 64bit. Any pointers much appreciated. I have followed below steps. 1. make X86_64_defconfig 2. make V=1 (comiler shows that -m64 is getting used). 3. [root@grpRHEL2 linux-2.6.32.60]# file vmlinux vmlinux.o vmlinux: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), statically linked, not stripped vmlinux.o: ELF 64-bit LSB relocatable, x86-64, version 1 (SYSV), not stripped 4. bzImage does not say x86_64 boot. root@grpRHEL2 boot]# pwd /root/lin_2/linux-2.6.32.60/arch/x86_64/boot [root@grpRHEL2 boot]# file bzImage bzImage: symbolic link to `../../x86/boot/bzImage' [root@grpRHEL2 boot]# file ../../x86/boot/bzImage ../../x86/boot/bzImage: Linux kernel x86 boot executable bzImage, version 2.6.32.60 (root@grpRHEL2) #1 SM, RO-rootFS, swap_dev 0x3, Normal VGA 5. After boot 'uname -a' , shows this. Linux 2.6.29.6 #1 SMP Mon Mar 25 16:20:30 IST 2013 i686 GNU/Linux

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Fwd: dump utility[sorry for last spam, it was tab+enter]
by jack rule May 28, 2013

May 28, 2013

Hi, I have to implement a dump utility which can dump the physical memory just before the crash/(crash +reboot). if anybody have worked with it pls share any info/structure as i din't find anything yet on google. regards J

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mss for tcp segment
by Varun Sharma May 28, 2013

May 28, 2013

Hi, What is the value of mss for tcp segment.

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dump utility
by jack rule May 28, 2013

May 28, 2013

Hi, I have to implement a dump utility which can dump the physical memory just before the crash.

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zambezi/bulldozer support
by Littlefield, Tyler May 28, 2013

May 28, 2013

I have kernel 3.9.3 and am not seeing anything that would resemble support for this processor. Closest is AMD elan support. Does this exist yet? Is there a way to set it up to compile for the zambezi/bulldozer processors? Most notable would be a way to just give -march=native to gcc since 4.8 supports this processor IIRC. Thanks, -- Take care, Ty http://tds-solutions.net The aspen project: a barebones light-weight mud engine: http://code.google.com/p/aspenmud He that will not reason is a bigot; he that cannot reason is a fool; he that dares not reason is a slave.

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File System : Error Checking
by Dibyayan Chakraborty May 27, 2013

May 27, 2013

Hi, I was just wondering how various error checking is done in the file systems. The main object is to check for file system corruptions resulted by various kinds of physical storage failures. Ext4 file systems provides this feature through various check sum. But i am not sure of the actual process how it is done. Any kind of explanation will be helpfull. -- With Regards Dibyayan Chakraborty

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lookup function return value in inode_operations
by Sankar P May 27, 2013

May 27, 2013

Hi, What is the return value of the lookup function under the inode_operations struct ? I see that the function gets a dentry as a parameter, which can be used to associate an inode. For example: If we have: struct dentry * somefs_lookup(struct inode *parent_inode, struct dentry *child_dentry, unsigned int flags) { d_add(child_dentry, inode); } so, what is the meaning of the return "struct dentry" in this lookup function ? In some simple filesystems that I saw, they return NULL here and it seem to work just fine. So what is that the lookup function should do if we are implementing our own filesystem ? Thanks. -- Sankar P http://psankar.blogspot.com

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