From 70a7bfb1e515b03e54491254a4375cdfb9515227 Mon Sep 17 00:00:00 2001 From: Damien Le Moal Date: Sat, 13 Apr 2024 09:41:20 +0900 Subject: [PATCH] PCI: rockchip-host: Wait 100ms after reset before starting configuration MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit PCIe r6.0, sec 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 deasserting PERST# using the ep_gpio GPIO. Link: https://lore.kernel.org/linux-pci/20240413004120.1099089-3-dlemoal@kernel.org Suggested-by: Bjorn Helgaas Signed-off-by: Damien Le Moal Signed-off-by: Krzysztof Wilczyński Signed-off-by: Bjorn Helgaas Reviewed-by: Manivannan Sadhasivam --- 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 84b711cad267..b2865fb5a70d 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 PCIe r6.0, sec 6.6.1. + */ +#define PCIE_T_RRS_READY_MS 100 + /* * PCIe r6.0, sec 5.3.3.2.1 * Recommends 1ms to 10ms timeout to check L2 ready.