[PATCH 2/2] ahci_xgene: Fix the dma state machine lockup for the ATA_CMD_PACKET PIO mode command.

[sergei.shtylyov@cogentembedded.com (Sergei Shtylyov)]

Hello.

On 12/16/2014 07:49 PM, Suman Tripathi wrote:

> This patch addresses the issue with ATA_CMD_PACKET pio mode
> command for enumeration and device detection with ATAPI devices.It is the
> same issue as in patch

> www.spinics.net/lists/linux-ide/msg49092.html

> Signed-off-by: Suman Tripathi <stripathi@apm.com>
> ---
>   drivers/ata/ahci_xgene.c | 12 +++++++-----
>   1 file changed, 7 insertions(+), 5 deletions(-)

> diff --git a/drivers/ata/ahci_xgene.c b/drivers/ata/ahci_xgene.c
> index 0ffd3c9..9730907 100644
> --- a/drivers/ata/ahci_xgene.c
> +++ b/drivers/ata/ahci_xgene.c
> @@ -125,10 +125,11 @@ static int xgene_ahci_restart_engine(struct ata_port *ap)
>    * xgene_ahci_qc_issue - Issue commands to the device
>    * @qc: Command to issue
>    *
> - * Due to Hardware errata for IDENTIFY DEVICE command, the controller cannot
> - * clear the BSY bit after receiving the PIO setup FIS. This results in the dma
> - * state machine goes into the CMFatalErrorUpdate state and locks up. By
> - * restarting the dma engine, it removes the controller out of lock up state.
> + * Due to Hardware errata for IDENTIFY DEVICE command and COMMAND PACKET

    Just PACKET.

> + * command of ATAPI protocol set, the controller cannot clear the BSY bit
> + * after receiving the PIO setup FIS. This results in the dma state machine

    DMA.

> + * goes into the CMFatalErrorUpdate state and locks up. By restarting the

    s/goes/going/.

> + * dma engine, it removes the controller out of lock up state.

    DMA again.

>    */
>   static unsigned int xgene_ahci_qc_issue(struct ata_queued_cmd *qc)
>   {
[...]

MBR, Sergei