On 6/5/22 05:53, Sergey Shtylyov 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:
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
pio modes) but the pio mode that will be used for that device, we should
reword, no ?
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.
>
> Fixes: d9027470b886 ("[libata] Add ATA transport class")
> Signed-off-by: Sergey Shtylyov <s.shtylyov@xxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
>
> ---
> This patch is against the 'master' branch of Damien's 'libata.git' repo.
>
> drivers/ata/libata-transport.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> Index: libata/drivers/ata/libata-transport.c
> ===================================================================
> --- libata.orig/drivers/ata/libata-transport.c
> +++ libata/drivers/ata/libata-transport.c
> @@ -196,7 +196,7 @@ static struct {
> { XFER_PIO_0, "XFER_PIO_0" },
> { XFER_PIO_SLOW, "XFER_PIO_SLOW" }
> };
> -ata_bitfield_name_match(xfer,ata_xfer_names)
> +ata_bitfield_name_search(xfer, ata_xfer_names)
>
> /*
> * ATA Port attributes
--
Damien Le Moal
Western Digital Research
