Re: [PATCH] ata: pata_marvell: Check the 'bmdma_addr' beforing reading

[Damien Le Moal <damien.lemoal@opensource.wdc.com>]

On 4/20/22 21:21, Zheyu Ma wrote:
> Before detecting the cable type on the dma bar, the driver should check
> whether the 'bmdma_addr' is zero, which means the adapter does not
> support DMA, otherwise we will get the following error:
> 
> [    5.146634] Bad IO access at port 0x1 (return inb(port))
> [    5.147206] WARNING: CPU: 2 PID: 303 at lib/iomap.c:44 ioread8+0x4a/0x60
> [    5.150856] RIP: 0010:ioread8+0x4a/0x60
> [    5.160238] Call Trace:
> [    5.160470]  <TASK>
> [    5.160674]  marvell_cable_detect+0x6e/0xc0 [pata_marvell]
> [    5.161728]  ata_eh_recover+0x3520/0x6cc0
> [    5.168075]  ata_do_eh+0x49/0x3c0
> 
> Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
> ---
>  drivers/ata/pata_marvell.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/ata/pata_marvell.c b/drivers/ata/pata_marvell.c
> index 0c5a51970fbf..d2922699be5e 100644
> --- a/drivers/ata/pata_marvell.c
> +++ b/drivers/ata/pata_marvell.c
> @@ -77,7 +77,9 @@ static int marvell_cable_detect(struct ata_port *ap)
>  	switch(ap->port_no)
>  	{
>  	case 0:
> -		if (ioread8(ap->ioaddr.bmdma_addr + 1) & 1)
> +		if (!ap->ioaddr.bmdma_addr)
> +			return ATA_CBL_PATA_UNK;
> +		else if (ioread8(ap->ioaddr.bmdma_addr + 1) & 1)

No need for the "else" here.

>  			return ATA_CBL_PATA40;
>  		return ATA_CBL_PATA80;
>  	case 1: /* Legacy SATA port */


-- 
Damien Le Moal
Western Digital Research