Re: [PATCH v2] libata: disable runtime pm for hotpluggable port
From: Matt
Date: Wed Mar 14 2012 - 18:54:53 EST
On Tue, Mar 13, 2012 at 2:57 AM, Lin Ming <ming.m.lin@xxxxxxxxx> wrote:
> Currently, hotplug doesn't work if port is already runtime suspended.
> For now, we simply disable runtime pm for hotpluggable port.
> Later, we should add runtime pm support for hotpluggable port too.
>
> Bug report:
> https://lkml.org/lkml/2012/2/19/70
>
> v2:
> - Use bit 2 and 3 for flags ATA_FLAG_EXTERNAL and ATA_FLAG_PLUGGABLE.
>
> TODO: add similar hotpluggable port check for controllers other than
> AHCI.
>
> Reported-and-tested-by: Jiri Slaby <jslaby@xxxxxxx>
> Reported-and-tested-by: cwillu@xxxxxxxxxx
> Reported-and-tested-by: jackdachef@xxxxxxxxx
> Signed-off-by: Lin Ming <ming.m.lin@xxxxxxxxx>
> ---
> drivers/ata/ahci.c | 3 +++
> drivers/ata/ahci.h | 3 +++
> drivers/ata/libahci.c | 20 ++++++++++++++++++++
> drivers/ata/libata-transport.c | 6 ++++--
> include/linux/libata.h | 2 ++
> 5 files changed, 32 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
> index d07bf03..02e93ff 100644
> --- a/drivers/ata/ahci.c
> +++ b/drivers/ata/ahci.c
> @@ -1145,6 +1145,9 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
> if (hpriv->cap & HOST_CAP_PMP)
> pi.flags |= ATA_FLAG_PMP;
>
> + if (hpriv->cap & HOST_CAP_SXS)
> + pi.flags |= ATA_FLAG_EXTERNAL;
> +
> ahci_set_em_messages(hpriv, &pi);
>
> if (ahci_broken_system_poweroff(pdev)) {
> diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
> index b175000..92f7172 100644
> --- a/drivers/ata/ahci.h
> +++ b/drivers/ata/ahci.h
> @@ -172,6 +172,9 @@ enum {
> PORT_CMD_ALPE = (1 << 26), /* Aggressive Link PM enable */
> PORT_CMD_ATAPI = (1 << 24), /* Device is ATAPI */
> PORT_CMD_FBSCP = (1 << 22), /* FBS Capable Port */
> + PORT_CMD_ESP = (1 << 21), /* External SATA Port */
> + PORT_CMD_MPSP = (1 << 19), /* Mechanical Presence Switch Attached to Port */
> + PORT_CMD_HPCP = (1 << 18), /* Hot Plug Capable Port */
> PORT_CMD_PMP = (1 << 17), /* PMP attached */
> PORT_CMD_LIST_ON = (1 << 15), /* cmd list DMA engine running */
> PORT_CMD_FIS_ON = (1 << 14), /* FIS DMA engine running */
> diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
> index a72bfd0..7d72d3c 100644
> --- a/drivers/ata/libahci.c
> +++ b/drivers/ata/libahci.c
> @@ -1097,6 +1097,23 @@ static void ahci_port_init(struct device *dev, struct ata_port *ap,
> writel(1 << port_no, mmio + HOST_IRQ_STAT);
> }
>
> +static bool ahci_port_pluggable(struct ata_port *ap)
> +{
> + void __iomem *port_mmio = ahci_port_base(ap);
> + u32 cmd;
> +
> + cmd = readl(port_mmio + PORT_CMD);
> +
> + if ((ap->flags & ATA_FLAG_EXTERNAL) &&
> + (cmd & PORT_CMD_ESP))
> + return true;
> +
> + if (cmd & (PORT_CMD_MPSP | PORT_CMD_HPCP))
> + return true;
> +
> + return false;
> +}
> +
> void ahci_init_controller(struct ata_host *host)
> {
> struct ahci_host_priv *hpriv = host->private_data;
> @@ -1112,6 +1129,9 @@ void ahci_init_controller(struct ata_host *host)
> if (ata_port_is_dummy(ap))
> continue;
>
> + if (ahci_port_pluggable(ap))
> + ap->flags |= ATA_FLAG_PLUGGABLE;
> +
> ahci_port_init(host->dev, ap, i, mmio, port_mmio);
> }
>
> diff --git a/drivers/ata/libata-transport.c b/drivers/ata/libata-transport.c
> index 74aaee3..a7166b9 100644
> --- a/drivers/ata/libata-transport.c
> +++ b/drivers/ata/libata-transport.c
> @@ -292,8 +292,10 @@ int ata_tport_add(struct device *parent,
> }
>
> device_enable_async_suspend(dev);
> - pm_runtime_set_active(dev);
> - pm_runtime_enable(dev);
> + if (!(ap->flags & ATA_FLAG_PLUGGABLE)) {
> + pm_runtime_set_active(dev);
> + pm_runtime_enable(dev);
> + }
>
> transport_add_device(dev);
> transport_configure_device(dev);
> diff --git a/include/linux/libata.h b/include/linux/libata.h
> index cafc09a..f46961d 100644
> --- a/include/linux/libata.h
> +++ b/include/linux/libata.h
> @@ -187,6 +187,8 @@ enum {
> ATA_FLAG_SLAVE_POSS = (1 << 0), /* host supports slave dev */
> /* (doesn't imply presence) */
> ATA_FLAG_SATA = (1 << 1),
> + ATA_FLAG_EXTERNAL = (1 << 2), /* Controller supports external SATA */
> + ATA_FLAG_PLUGGABLE = (1 << 3), /* Port is hotpluggable */
> ATA_FLAG_NO_ATAPI = (1 << 6), /* No ATAPI support */
> ATA_FLAG_PIO_DMA = (1 << 7), /* PIO cmds via DMA */
> ATA_FLAG_PIO_LBA48 = (1 << 8), /* Host DMA engine is LBA28 only */
> --
> 1.7.2.5
>
>
>
Hi Lin Ming,
thanks for CCing on the updated patch
I just finished testing it with 3.3-rc7 and it works as advertised
Kind Regards
Matt
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/