Messages in this thread |  | | Subject | Re: [PATCH] ata: Disable AHCI ALPM feature for Ampere Computing eMAG SATA | From | Hans de Goede <> | Date | Mon, 27 Aug 2018 21:08:35 +0200 |
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Hi,
On 27-08-18 20:47, Suman Tripathi wrote: > Due to hardware errata, Ampere Computing eMAG SATA can't support > AHCI ALPM feature. This patch disables the AHCI ALPM feature for > eMAG SATA. > > Signed-off-by: Suman Tripathi <stripathi@amperecomputing.com> > Signed-off-by: Rameshwar Prasad Sahu <rameshwar.sahu@amperecomputing.com>
Thank you for the patch. 2 remarks:
1) The ata code is maintained by Jens Axboe (added to the Cc) now, this is a very recent change, which still has to hit MAINTAINERS
2) See below
> --- > drivers/ata/ahci_platform.c | 13 ++++++++++++- > 1 file changed, 12 insertions(+), 1 deletion(-) > > diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c > index 99f9a89..0d0233e 100644 > --- a/drivers/ata/ahci_platform.c > +++ b/drivers/ata/ahci_platform.c > @@ -26,7 +26,7 @@ > > #define DRV_NAME "ahci" > > -static const struct ata_port_info ahci_port_info = { > +static struct ata_port_info ahci_port_info = { > .flags = AHCI_FLAG_COMMON, > .pio_mask = ATA_PIO4, > .udma_mask = ATA_UDMA6,
Please do not remove const here, if you need to make a shared info struct like this non const you are usually doing something wrong (see below).
> @@ -41,6 +41,8 @@ static int ahci_probe(struct platform_device *pdev) > { > struct device *dev = &pdev->dev; > struct ahci_host_priv *hpriv; > + struct acpi_device_info *info; > + acpi_status status; > int rc; > > hpriv = ahci_platform_get_resources(pdev); > @@ -57,6 +59,15 @@ static int ahci_probe(struct platform_device *pdev) > if (of_device_is_compatible(dev->of_node, "hisilicon,hisi-ahci")) > hpriv->flags |= AHCI_HFLAG_NO_FBS | AHCI_HFLAG_NO_NCQ; > > + status = acpi_get_object_info(ACPI_HANDLE(dev), &info); > + if (ACPI_SUCCESS(status)) { > + if (info->valid & ACPI_VALID_HID) { > + if (!strcmp("APMC0D33", info->hardware_id.string)) > + ahci_port_info.flags |= ATA_FLAG_NO_LPM; > + } > + ACPI_FREE(info); > + } > + > rc = ahci_platform_init_host(pdev, hpriv, &ahci_port_info, > &ahci_platform_sht); > if (rc)
The normal way to get specific behavior for a specific ACPI HID is to put the HID in the ahci_acpi_match table and use the acpi_device_id field to pass some flags (or a pointer).
So the proper way to fix this is to do something like this:
1) Add:
static const struct ata_port_info ahci_port_info_nolpm = { .flags = AHCI_FLAG_COMMON | ATA_FLAG_NO_LPM, .pio_mask = ATA_PIO4, .udma_mask = ATA_UDMA6, .port_ops = &ahci_platform_ops, };
2) Modify ahci_acpi_match table to:
static const struct acpi_device_id ahci_acpi_match[] = { { "APMC0D33", (unsigned long)&ahci_port_info_nolpm }, { ACPI_DEVICE_CLASS(PCI_CLASS_STORAGE_SATA_AHCI, 0xffffff) }, {}, };
3) In ahci_probe() do:
const struct ata_port_info *port;
...
port = acpi_device_get_match_data(dev); if (!port) port = &ahci_port_info;
rc = ahci_platform_init_host(pdev, hpriv, port, &ahci_platform_sht);
Regards,
Hans
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