| Message ID | 1420453305-15986-2-git-send-email-stripathi@apm.com |
|---|---|
| State | Not Applicable |
| Delegated to: | David Miller |
| Headers | show |
Hello.
On 1/5/2015 1:21 PM, Suman Tripathi wrote:
Your patch summary seems too long.
> This patch implements the function xgene_ahci_poll_reg_val to poll
> PxCI for multiple IDENTIFY DEVICE commands to finish before
> restarting the DMA engine in case of Port Multiplier.
> Signed-off-by: Suman Tripathi <stripathi@apm.com>
> ---
> drivers/ata/ahci_xgene.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 54 insertions(+), 2 deletions(-)
> diff --git a/drivers/ata/ahci_xgene.c b/drivers/ata/ahci_xgene.c
> index 0f8538f..2180223 100644
> --- a/drivers/ata/ahci_xgene.c
> +++ b/drivers/ata/ahci_xgene.c
> @@ -105,17 +105,69 @@ static int xgene_ahci_init_memram(struct xgene_ahci_context *ctx)
> }
>
> /**
> + * xgene_ahci_poll_reg_val- Poll a register on a specific value.
> + * @ap : ATA port of interest.
> + * @reg : Register of interest.
> + * @val : Value to be attained.
> + * @interval : waiting interval for polling.
> + * @timeout : timeout for achieving the value.
> + */
> +static int xgene_ahci_poll_reg_val(struct ata_port *ap,
> + void __iomem *reg, unsigned
> + int val, unsigned long interval,
> + unsigned long timeout)
> +{
> + unsigned long deadline;
> + unsigned int tmp;
> +
> + tmp = ioread32(reg);
> + deadline = ata_deadline(jiffies, timeout);
> +
> + while ((tmp != val) && (time_before(jiffies, deadline))) {
Parens around the operands of && are not needed, especially around the
right one.
> + ata_msleep(ap, interval);
> + tmp = ioread32(reg);
> + }
> +
> + return tmp;
> +}
> +
> +/**
> * xgene_ahci_restart_engine - Restart the dma engine.
> * @ap : ATA port of interest
> *
> - * Restarts the dma engine inside the controller.
> + * Waits for completion of multiple commands and restarts
> + * the DMA engine inside the controller.
> */
> static int xgene_ahci_restart_engine(struct ata_port *ap)
> {
> struct ahci_host_priv *hpriv = ap->host->private_data;
> + struct ahci_port_priv *pp = ap->private_data;
> + void __iomem *port_mmio = ahci_port_base(ap);
> + u32 fbs;
> +
> + /*
> + * In case of PMP multiple IDENTIFY DEVICE commands can be
> + * issued inside PxCI. So need to poll PxCI for the
> + * completion of outstanding IDENTIFY DEVICE commands before
> + * we restart the DMA engine.
> + */
> + if (xgene_ahci_poll_reg_val(ap, port_mmio +
> + PORT_CMD_ISSUE, 0x0, 1, 100))
> + return -EBUSY;
>
> ahci_stop_engine(ap);
> ahci_start_fis_rx(ap);
> +
> + /*
> + * Enable the PxFBS.FBS_EN bit as it
> + * gets cleared due to stop engine.
s/stop/stopping the/.
[...]
MBR, Sergei
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diff --git a/drivers/ata/ahci_xgene.c b/drivers/ata/ahci_xgene.c index 0f8538f..2180223 100644 --- a/drivers/ata/ahci_xgene.c +++ b/drivers/ata/ahci_xgene.c @@ -105,17 +105,69 @@ static int xgene_ahci_init_memram(struct xgene_ahci_context *ctx) } /** + * xgene_ahci_poll_reg_val- Poll a register on a specific value. + * @ap : ATA port of interest. + * @reg : Register of interest. + * @val : Value to be attained. + * @interval : waiting interval for polling. + * @timeout : timeout for achieving the value. + */ +static int xgene_ahci_poll_reg_val(struct ata_port *ap, + void __iomem *reg, unsigned + int val, unsigned long interval, + unsigned long timeout) +{ + unsigned long deadline; + unsigned int tmp; + + tmp = ioread32(reg); + deadline = ata_deadline(jiffies, timeout); + + while ((tmp != val) && (time_before(jiffies, deadline))) { + ata_msleep(ap, interval); + tmp = ioread32(reg); + } + + return tmp; +} + +/** * xgene_ahci_restart_engine - Restart the dma engine. * @ap : ATA port of interest * - * Restarts the dma engine inside the controller. + * Waits for completion of multiple commands and restarts + * the DMA engine inside the controller. */ static int xgene_ahci_restart_engine(struct ata_port *ap) { struct ahci_host_priv *hpriv = ap->host->private_data; + struct ahci_port_priv *pp = ap->private_data; + void __iomem *port_mmio = ahci_port_base(ap); + u32 fbs; + + /* + * In case of PMP multiple IDENTIFY DEVICE commands can be + * issued inside PxCI. So need to poll PxCI for the + * completion of outstanding IDENTIFY DEVICE commands before + * we restart the DMA engine. + */ + if (xgene_ahci_poll_reg_val(ap, port_mmio + + PORT_CMD_ISSUE, 0x0, 1, 100)) + return -EBUSY; ahci_stop_engine(ap); ahci_start_fis_rx(ap); + + /* + * Enable the PxFBS.FBS_EN bit as it + * gets cleared due to stop engine. + */ + if (pp->fbs_supported) { + fbs = readl(port_mmio + PORT_FBS); + writel(fbs | PORT_FBS_EN, port_mmio + PORT_FBS); + fbs = readl(port_mmio + PORT_FBS); + } + hpriv->start_engine(ap); return 0; @@ -372,7 +424,7 @@ static struct ata_port_operations xgene_ahci_ops = { }; static const struct ata_port_info xgene_ahci_port_info = { - .flags = AHCI_FLAG_COMMON, + .flags = AHCI_FLAG_COMMON | ATA_FLAG_PMP, .pio_mask = ATA_PIO4, .udma_mask = ATA_UDMA6, .port_ops = &xgene_ahci_ops,
This patch implements the function xgene_ahci_poll_reg_val to poll PxCI for multiple IDENTIFY DEVICE commands to finish before restarting the DMA engine in case of Port Multiplier. Signed-off-by: Suman Tripathi <stripathi@apm.com> --- drivers/ata/ahci_xgene.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 54 insertions(+), 2 deletions(-) -- 1.8.2.1 -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html