From: Suman Tripathi Date: Mon, 29 Dec 2014 03:22:47 +0000 (+0530) Subject: ahci_xgene: Fix the DMA state machine lockup for the ATA_CMD_PACKET PIO mode command. X-Git-Tag: v3.19-rc6~26^2~10 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=1102407bb71;p=karo-tx-linux.git ahci_xgene: Fix the DMA state machine lockup for the ATA_CMD_PACKET PIO mode command. This patch addresses the issue with ATA_CMD_PACKET pio mode command for enumeration and device detection with ATAPI devices. The X-Gene AHCI controller has an errata in which it cannot clear the BSY bit after the PIO setup FIS. The dma state machine enters CMFatalErrorUpdate state and locks up. Signed-off-by: Suman Tripathi Signed-off-by: Tejun Heo --- diff --git a/drivers/ata/ahci_xgene.c b/drivers/ata/ahci_xgene.c index f190b92786e4..cbcd20810355 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 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 + * going into the CMFatalErrorUpdate state and locks up. By restarting the + * DMA engine, it removes the controller out of lock up state. */ static unsigned int xgene_ahci_qc_issue(struct ata_queued_cmd *qc) { @@ -137,7 +138,8 @@ static unsigned int xgene_ahci_qc_issue(struct ata_queued_cmd *qc) struct xgene_ahci_context *ctx = hpriv->plat_data; int rc = 0; - if (unlikely(ctx->last_cmd[ap->port_no] == ATA_CMD_ID_ATA)) + if (unlikely((ctx->last_cmd[ap->port_no] == ATA_CMD_ID_ATA) || + (ctx->last_cmd[ap->port_no] == ATA_CMD_PACKET))) xgene_ahci_restart_engine(ap); rc = ahci_qc_issue(qc);