Re: [PATCH next] ide: fix PowerMac bootup oops

[Bartlomiej Zolnierkiewicz]

Hi Hugh,

On Monday 08 June 2009 22:45:28 Hugh Dickins wrote:
> PowerMac bootup with CONFIG_IDE=y oopses in ide_pio_cycle_time():
> because "ide: try to use PIO Mode 0 during probe if possible" causes
> pmac_ide_set_pio_mode() now to be called before drive->id has been set.

Good spotting, I overlooked this aspect of the change while testing it
with piix host driver..

> It does the right thing if id is not set, so long as we check for that.

After auditing some other host drivers I see that drive->id can be used
also directly in ->set_pio_mode methods..

Could you please instead try moving ->id allocation from probe_for_drive()
to ide_port_alloc_devices() (this would fix all such issues for good) and
verify that it also fixes the oops?

> Signed-off-by: Hugh Dickins <hugh.dickins@xxxxxxxxxxxxx>
> ---
> 
>  drivers/ide/ide-timings.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- lnext/drivers/ide/ide-timings.c	2009-04-08 18:25:55.000000000 +0100
> +++ linux/drivers/ide/ide-timings.c	2009-06-03 19:45:58.000000000 +0100
> @@ -84,7 +84,7 @@ u16 ide_pio_cycle_time(ide_drive_t *driv
>  	struct ide_timing *t = ide_timing_find_mode(XFER_PIO_0 + pio);
>  	u16 cycle = 0;
>  
> -	if (id[ATA_ID_FIELD_VALID] & 2) {
> +	if (id && (id[ATA_ID_FIELD_VALID] & 2)) {
>  		if (ata_id_has_iordy(drive->id))
>  			cycle = id[ATA_ID_EIDE_PIO_IORDY];
>  		else
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