[SeaBIOS] [PATCH] ata: send TEST UNIT READY correctly

[fellaw at gmx.net]

Confirmed working.

Paolo Bonzini schrieb:
> The ATAPI driver does not need to support writes, but it does needs to
> avoid the PIO transfer and DRQ check when TEST UNIT READY is sent.
> Since TEST UNIT READY has no payload, checking for not busy is enough.
>
> This fixes a timeout when booting from CD/DVD, which fellaw at gmx.net
> reported to cause boot failures.
>
> Signed-off-by: Paolo Bonzini<pbonzini at redhat.com>
> ---
>   src/ata.c |   14 ++++++++------
>   1 files changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/src/ata.c b/src/ata.c
> index 76e4f20..c37691a 100644
> --- a/src/ata.c
> +++ b/src/ata.c
> @@ -645,13 +645,15 @@ atapi_cmd_data(struct disk_op_s *op, void *cdbcmd, u16 blocksize)
>           ret = -2;
>           goto fail;
>       }
> -    if (!(status&  ATA_CB_STAT_DRQ)) {
> -        dprintf(6, "send_atapi_cmd : DRQ not set (status %02x)\n", status);
> -        ret = -3;
> -        goto fail;
> -    }
> +    if (blocksize) {
> +        if (!(status&  ATA_CB_STAT_DRQ)) {
> +            dprintf(6, "send_atapi_cmd : DRQ not set (status %02x)\n", status);
> +            ret = -3;
> +            goto fail;
> +        }
>
> -    ret = ata_pio_transfer(op, 0, blocksize);
> +        ret = ata_pio_transfer(op, 0, blocksize);
> +    }
>
>   fail:
>       // Enable interrupts