Re: [PATCH v3 10/23] ata: libahci_platform: Parse ports-implemented property in resources getter

Serge Semin
2022-05-12T14:32:15Z

On Thu, May 12, 2022 at 08:48:24AM +0200, Hannes Reinecke wrote:
> On 5/12/22 01:17, Serge Semin wrote:
> > The ports-implemented property is mainly used on the OF-based platforms
> > with no ports mapping initialized by a bootloader/BIOS firmware. Seeing
> > the same of_property_read_u32()-based pattern has already been implemented
> > in the generic AHCI LLDD (glue) driver and in the Mediatek, St AHCI
> > drivers let's move the property read procedure to the generic
> > ahci_platform_get_resources() method. Thus we'll have the forced ports
> > mapping feature supported for each OF-based platform which requires that,
> > and stop re-implementing the same pattern in there a bit simplifying the
> > code.
> >
> > Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> > ---
> > drivers/ata/ahci_mtk.c | 2 --
> > drivers/ata/ahci_platform.c | 3 ---
> > drivers/ata/ahci_st.c | 3 ---
> > drivers/ata/libahci_platform.c | 3 +++
> > 4 files changed, 3 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/ata/ahci_mtk.c b/drivers/ata/ahci_mtk.c
> > index 1f6c85fde983..c056378e3e72 100644
> > --- a/drivers/ata/ahci_mtk.c
> > +++ b/drivers/ata/ahci_mtk.c
> > @@ -118,8 +118,6 @@ static int mtk_ahci_parse_property(struct ahci_host_priv *hpriv,
> > SYS_CFG_SATA_EN);
> > }
> > - of_property_read_u32(np, "ports-implemented", &hpriv->force_port_map);
> > -
> > return 0;
> > }
> > diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c
> > index 28a8de5b48b9..9b56490ecbc3 100644
> > --- a/drivers/ata/ahci_platform.c
> > +++ b/drivers/ata/ahci_platform.c
> > @@ -56,9 +56,6 @@ static int ahci_probe(struct platform_device *pdev)
> > if (rc)
> > return rc;
> > - of_property_read_u32(dev->of_node,
> > - "ports-implemented", &hpriv->force_port_map);
> > -
> > if (of_device_is_compatible(dev->of_node, "hisilicon,hisi-ahci"))
> > hpriv->flags |= AHCI_HFLAG_NO_FBS | AHCI_HFLAG_NO_NCQ;
> > diff --git a/drivers/ata/ahci_st.c b/drivers/ata/ahci_st.c
> > index 7526653c843b..068621099c00 100644
> > --- a/drivers/ata/ahci_st.c
> > +++ b/drivers/ata/ahci_st.c
> > @@ -168,9 +168,6 @@ static int st_ahci_probe(struct platform_device *pdev)
> > st_ahci_configure_oob(hpriv->mmio);
> > - of_property_read_u32(dev->of_node,
> > - "ports-implemented", &hpriv->force_port_map);
> > -
> > err = ahci_platform_init_host(pdev, hpriv, &st_ahci_port_info,
> > &ahci_platform_sht);
> > if (err) {
> > diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
> > index 4e54e19f07b2..f7f9cac10cb1 100644
> > --- a/drivers/ata/libahci_platform.c
> > +++ b/drivers/ata/libahci_platform.c
> > @@ -512,6 +512,9 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev,
> > goto err_out;
> > }

> > + of_property_read_u32(dev->of_node,
> > + "ports-implemented", &hpriv->force_port_map);
> > +
> > if (child_nodes) {
> > for_each_child_of_node(dev->of_node, child) {
> > u32 port;
>
> What happens on the other platforms?
> Won't they register an error if that property isn't implemented?

No. The force_port_map field will be left unmodified (zero by default) in case
if the optional 'ports-implemented' property is unavailable. See the
of_property_read_u32_array() method kdoc:
https://elixir.bootlin.com/linux/latest/source/include/linux/of.h#L1261

-Sergey

>
> Cheers,
>
> Hannes
> --
> Dr. Hannes Reinecke Kernel Storage Architect
> hare@suse.de +49 911 74053 688
> SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
> HRB 36809 (AG Nürnberg), GF: Felix Imendörffer