Hello!
On 6/6/22 5:42 AM, Damien Le Moal wrote:
>> The {dma|pio|xfer}_mode sysfs files are incorrectly handled by the
>> ata_bitfield_name_match() macro which leads to reading such kind of
>> nonsense from them:
>>
>> $ cat /sys/class/ata_device/dev3.0/pio_mode
>> XFER_UDMA_7, XFER_UDMA_6, XFER_UDMA_5, XFER_UDMA_4, XFER_MW_DMA_4,
>> XFER_PIO_6, XFER_PIO_5, XFER_PIO_4, XFER_PIO_3, XFER_PIO_2, XFER_PIO_1,
>> XFER_PIO_0
>>
>> Using the correct ata_bitfield_name_search() macro fixes that:
>>
>> $ cat /sys/class/ata_device/dev3.0/pio_mode
>> XFER_PIO_4
>
> Looks good, but Documentation/ABI/testing/sysfs-ata says:
Completely forgot that the sysfs files are documented as ABIs... :-(
Hm, shouldn't that file be added to the libata's entry in MAINTAINERS?
> pio_mode: (RO) Transfer modes supported by the device when
> in PIO mode. Mostly used by PATA device.
>
> xfer_mode: (RO) Current transfer mode
>
> dma_mode: (RO) Transfer modes supported by the device when
> in DMA mode. Mostly used by PATA device.
>
> which seems incorrect/badly worded for pio_mode and dma_mode. Since these
> 2 sysfs attributes do not actually device the pio mask (list of supported
Device?
> pio modes) but the pio mode that will be used for that device, we should
> reword, no ?
Yes, of course. :-)
> What about:
>
> pio_mode: (RO) Transfer mode used by the device when
> in PIO mode. Mostly used by PATA device.
>
> xfer_mode: (RO) Current transfer mode
>
> dma_mode: (RO) Transfer mode used by the device when
> in DMA mode. Mostly used by PATA device.
Sounds quite tautological... :-)
What about:
{dma|pio}_mode: (RO) {DMA|PIO} transfer mode used by the device.
Mostly used by PATA devices.
I think this should be done in the same patch. Or would you prefer 2 patches?
[...]
MBR, Sergey
