On Fri, Apr 12, 2024 at 11:37:21AM +0900, Damien Le Moal wrote: > The PCI Express Base Specification r6.0, section 6.6.1, states that the > host should wait for at least 100 msec from the end of a conventional > reset (PERST# is de-asserted) before sending a configuration request to > ensure that the device is able to respond with a "Request Retry Status" > completion. > > Add the PCIE_T_RRS_READY_MS macro to define this wait time and modify > rockchip_pcie_host_init_port() to add this 100ms sleep after bringing > back PESRT# signal to high using the ep_gpio GPIO. s/PESRT#/PERST#/ s/bringing back PERST# signal to high/deasserting PERST#/ > Suggested-by: Bjorn Helgaas <helgaas@xxxxxxxxxx> > Signed-off-by: Damien Le Moal <dlemoal@xxxxxxxxxx> > --- > drivers/pci/controller/pcie-rockchip-host.c | 2 ++ > drivers/pci/pci.h | 7 +++++++ > 2 files changed, 9 insertions(+) > > diff --git a/drivers/pci/controller/pcie-rockchip-host.c b/drivers/pci/controller/pcie-rockchip-host.c > index fc868251e570..cbec71114825 100644 > --- a/drivers/pci/controller/pcie-rockchip-host.c > +++ b/drivers/pci/controller/pcie-rockchip-host.c > @@ -325,6 +325,8 @@ static int rockchip_pcie_host_init_port(struct rockchip_pcie *rockchip) > msleep(PCIE_T_PVPERL_MS); > gpiod_set_value_cansleep(rockchip->ep_gpio, 1); > > + msleep(PCIE_T_RRS_READY_MS); > + > /* 500ms timeout value should be enough for Gen1/2 training */ > err = readl_poll_timeout(rockchip->apb_base + PCIE_CLIENT_BASIC_STATUS1, > status, PCIE_LINK_UP(status), 20, > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > index 17fed1846847..c93ffc5e6e1f 100644 > --- a/drivers/pci/pci.h > +++ b/drivers/pci/pci.h > @@ -16,6 +16,13 @@ > /* Power stable to PERST# inactive from PCIe card Electromechanical Spec */ > #define PCIE_T_PVPERL_MS 100 > > +/* > + * End of conventional reset (PERST# de-asserted) to first configuration > + * request (device able to respond with a "Request Retry Status" completion), > + * from PCI Express Base Specification r6.0, section 6.6.1. "PCIe r6.0, sec 6.6.1" to match typical style, e.g., the reference just below. Whoever applies this can take care of this. > +#define PCIE_T_RRS_READY_MS 100 Thanks a lot for doing this; there are many similar places we can update to use this #define. > /* > * PCIe r6.0, sec 5.3.3.2.1 <PME Synchronization> > * Recommends 1ms to 10ms timeout to check L2 ready. > -- > 2.44.0 >
