Quick question about libata and hdparm

[Rogério Brito]

Dear people,

I have one small question regarding the libata drivers and the  
interaction with hdparm.

I am presently using PATA/IDE devices only, but some distributions  
provide kernels with libata by default (and some defconfigs also use  
libata even for IDE devices).

Using the usual IDE drivers, I can use/query various parameters with  
hdparm, like, for instance, the -m option, the -c option or even  
disabling DMA. With the libata drivers, this is all that I get:

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
lutz:~# hdparm /dev/sda

/dev/sda:
 IO_support    =  0 (default)
 readonly      =  0 (off)
 readahead     = 256 (on)
 geometry      = 48641/255/63, sectors = 781420655, start = 0
lutz:~# hdparm -c 1 /dev/sda

/dev/sda:
 setting 32-bit IO_support flag to 1
 HDIO_SET_32BIT failed: Invalid argument
 IO_support    =  0 (default)
lutz:~# hdparm -m 16 /dev/sda

/dev/sda:
 setting multcount to 16
 HDIO_SET_MULTCOUNT failed: Inappropriate ioctl for device
 HDIO_GET_MULTCOUNT failed: Inappropriate ioctl for device
lutz:~#
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Am I doing something incorrectly? I would like at least to understand  
what is happening and, if possible, to fine-tune some settings.

If necessary, please let me know and I will provide any further  
information that may be needed.


Thanks in advance, Rogério Brito.

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