Re: [PATCH 3/3] ide: don't enable IORDY at a probe time

[Sergei Shtylyov <sshtylyov@ru.mvista.com>]

Bartlomiej Zolnierkiewicz wrote:

> * Add 'unsigned long port_flags' field to ide_hwif_t.
>
> * Add IDE_PFLAG_PROBING port flag and keep it set during probing.
>
> * Fix ide_pio_need_iordy() to not enable IORDY at a probe time
>   (IORDY may lead to controller lock up on certain controllers
>    if the port is not occupied).
>
> Loosely based on the recent libata's fix by Tejun, thanks to Alan
> for the hint that IDE may also need it.
>
> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
[...]

> Index: b/drivers/ide/ide-xfer-mode.c
> ===================================================================
> --- a/drivers/ide/ide-xfer-mode.c
> +++ b/drivers/ide/ide-xfer-mode.c
> @@ -109,6 +109,12 @@ EXPORT_SYMBOL_GPL(ide_get_best_pio_mode)
>  
>  int ide_pio_need_iordy(ide_drive_t *drive, const u8 pio)
>  {
> +	/*
> +	 * IORDY may lead to controller lock up on certain controllers
> +	 * if the port is not occupied.
>   

   This is really strange -- shouldn't it be floating in this case, and 
so most sampled as 1? Who can pull it down on an empty port?..

> +	 */
> +	if (pio == 0 && (drive->hwif->port_flags & IDE_PFLAG_PROBING))
> +		return 0;
>   

   Now I'm seeing why there was a need to introduce the wrapper. :-)

MBR, Sergei