Re: [PATCH v2] libata: disable runtime pm for hotpluggable port

[Lin Ming]

On Mon, Apr 2, 2012 at 4:48 AM, Jiri Slaby <jslaby@xxxxxxx> wrote:
> On 03/13/2012 02:57 AM, Lin Ming 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.
>
> Any updates on this? The patches which introduced the bug are in -rc1
> now. Unlike this patch.

Jeff,

Any concern to apply this patch?

Regards,
Lin Ming

>
>> 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 */
>>
> --
> js
> suse labs
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