[mythtv-users] Help: issues in trying to enable DMA on hard drives for mythtv...

Michael T. Dean mtdean at thirdcontact.com
Fri Jun 3 07:33:53 UTC 2005


On 06/02/05 21:59, Robert McRostie wrote:

>	One of the remaining problems that I have is the Live TV output is jerky. After searching the net I think this is related to me not being able to get the drives to use DMA. If I record anything the play back seems to be ok.
>  
>
...

>00:02.5 IDE interface: Silicon Integrated Systems [SiS] 5513 [IDE] (rev 01) (prog-if 8a [Master SecP PriP])
>	Subsystem: Giga-byte Technology: Unknown device 5002
>	Flags: bus master, medium devsel, latency 128, IRQ 16
>	I/O ports at <unassigned>
>	I/O ports at <unassigned>
>	I/O ports at <unassigned>
>	I/O ports at <unassigned>
>	I/O ports at f000 [size=16]
>  
>
...

>After searching for this on the internet I found the command hdparm -d1 /dev/hd? Which should enable dma access. But this does not work. I get an error stating
>
>HID0_SET_DMA failed: Operation not permitted
>  
>
a) When posting an error message please make sure you post the correct 
error message (HDIO_SET_DMA).  HID0_SET_DMA (if it existed) would be far 
more likely to be a USB subsystem error than IDE error.
b) Search on Google for (with quotes an pluses):
+"HDIO_SET_DMA" +failed +"Operation not permitted"
and you'll be amazed at how many other people have the same problem.

Basically, your kernel does not have support for the SIS chipset.

>Anyway, I have recompiled the Kernel (which is 2.6.9 do to the custom driver for the DVICO card) to support the IDE controller and this did not make any difference. I am using a Gigabit mother board model GA-8S661FXM-775 with a p4 on it. A pretty quick machine for this task.
>  
>
Did you compile the support into the kernel (i.e. it cannot be a 
module)?  Did you update your bootloader (GRUB or LILO)?  Did you reboot 
the system and select the new kernel?

Note, also, that if you have support for some kernel options (such as 
Generic PCI IDE Chipset Support a.k.a. CONFIG_BLK_DEV_GENERIC), they 
will typically prevent loading of the SiS support (i.e. the generic IDE 
support is tried first, and it works, so the kernel doesn't try the SiS 
support).

Mike


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