Re: [PATCH] PCI: brcmstb: Assert fundamental reset on initialization

From: Jim Quinlan
Date: Sat May 09 2020 - 18:13:51 EST


On Thu, May 7, 2020 at 1:20 PM Nicolas Saenz Julienne
<nsaenzjulienne@xxxxxxx> wrote:
>
> While preparing the driver for upstream this detail was missed.
>
> If not asserted during the initialization process, devices connected on
> the bus will not be made aware of the internal reset happening. This,
> potentially resulting in unexpected behavior.
Hi Nicolas,
I believe that most chips by design have the PERST signal asserted by
default during start-up but this will certainly cover any that do not.
Looks good.
Regards,
Jim
>
> Fixes: c0452137034b ("PCI: brcmstb: Add Broadcom STB PCIe host controller driver")
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@xxxxxxx>
> ---
> drivers/pci/controller/pcie-brcmstb.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
> index 0b97b94c4a9a..795a03be4150 100644
> --- a/drivers/pci/controller/pcie-brcmstb.c
> +++ b/drivers/pci/controller/pcie-brcmstb.c
> @@ -699,6 +699,7 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
>
> /* Reset the bridge */
> brcm_pcie_bridge_sw_init_set(pcie, 1);
> + brcm_pcie_perst_set(pcie, 1);
>
> usleep_range(100, 200);
>
> --
> 2.26.2
>