Re: [PATCH 3/3] ahci: st: st_configure_oob must be called after IP is clocked.

From: Lee Jones
Date: Mon Mar 02 2015 - 12:03:54 EST


On Mon, 02 Mar 2015, Peter Griffin wrote:

> Currently the ahci_st driver will hang the system on probe, as the
> st_configure_oob function does some register writes before the IP
> is clocked. This patch moves the function call to after
> ahci_platform_enable_resources (which enables the IP clock), and
> resolves the hang.
>
> Addtionally st_ahci_configure_oob should be called in the st_ahci_resume
> function, so we also rectify that ensuring it is also called after
> the IP clock has been enabled.
>
> Signed-off-by: Peter Griffin <peter.griffin@xxxxxxxxxx>
> ---
> drivers/ata/ahci_st.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)

I suspect we might find a few issues like this now we're not using
'clk_ignore_unused'.

Acked-by: Lee Jones <lee.jones@xxxxxxxxxx>

> diff --git a/drivers/ata/ahci_st.c b/drivers/ata/ahci_st.c
> index bc971af..ea0ff00 100644
> --- a/drivers/ata/ahci_st.c
> +++ b/drivers/ata/ahci_st.c
> @@ -68,8 +68,6 @@ static int st_ahci_deassert_resets(struct device *dev)
> }
> }
>
> - st_ahci_configure_oob(drv_data->hpriv->mmio);
> -
> if (drv_data->sw_rst) {
> err = reset_control_deassert(drv_data->sw_rst);
> if (err) {
> @@ -172,6 +170,8 @@ static int st_ahci_probe(struct platform_device *pdev)
> if (err)
> return err;
>
> + st_ahci_configure_oob(drv_data->hpriv->mmio);
> +
> err = ahci_platform_init_host(pdev, hpriv, &st_ahci_port_info,
> &ahci_platform_sht);
> if (err) {
> @@ -222,6 +222,8 @@ static int st_ahci_resume(struct device *dev)
> return err;
> }
>
> + st_ahci_configure_oob(drv_data->hpriv->mmio);
> +
> return ahci_platform_resume_host(dev);
> }
> #endif

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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