Allow access to config space of PCIe Root Port (which is always present on the root bus) even when PCIe link is down or no card is connected.

Signed-off-by: Pali Rohár pali@kernel.org --- drivers/pci/pci-aardvark.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/pci/pci-aardvark.c b/drivers/pci/pci-aardvark.c index ccaeecaca8e3..c795ef10b884 100644 --- a/drivers/pci/pci-aardvark.c +++ b/drivers/pci/pci-aardvark.c @@ -645,11 +645,8 @@ retry: * @pcie: The PCI device to access * * Wait up to 1 second for link training to be accomplished. - * - * Return 1 (true) if link training ends up with link up success. - * Return 0 (false) if link training ends up with link up failure. */ -static int pcie_advk_wait_for_link(struct pcie_advk *pcie) +static void pcie_advk_wait_for_link(struct pcie_advk *pcie) { int retries;

@@ -657,15 +654,13 @@ static int pcie_advk_wait_for_link(struct pcie_advk *pcie) for (retries = 0; retries < LINK_MAX_RETRIES; retries++) { if (pcie_advk_link_up(pcie)) { printf("PCIe: Link up\n"); - return 0; + return; }

udelay(LINK_WAIT_TIMEOUT); }

printf("PCIe: Link down\n"); - - return -ETIMEDOUT; }

/* @@ -898,8 +893,7 @@ static int pcie_advk_setup_hw(struct pcie_advk *pcie) return -EINVAL;

/* Wait for PCIe link up */ - if (pcie_advk_wait_for_link(pcie)) - return -ENXIO; + pcie_advk_wait_for_link(pcie);

return 0; }

Code is changing PCIe controller from Command mode to Direct mode.

Signed-off-by: Pali Rohár pali@kernel.org --- drivers/pci/pci-aardvark.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/pci-aardvark.c b/drivers/pci/pci-aardvark.c index c795ef10b884..4f7e61ecf166 100644 --- a/drivers/pci/pci-aardvark.c +++ b/drivers/pci/pci-aardvark.c @@ -757,7 +757,7 @@ static int pcie_advk_setup_hw(struct pcie_advk *pcie) int i, wins; u32 reg;

- /* Set to Direct mode */ + /* Set from Command to Direct mode */ reg = advk_readl(pcie, ADVK_CORE_CTRL_CONFIG); reg &= ~ADVK_CORE_CTRL_CONFIG_COMMAND_MODE; advk_writel(pcie, reg, ADVK_CORE_CTRL_CONFIG);

On 2/15/22 11:23, Pali Rohár wrote:

If a PIO request is executed while link-down, the whole controller gets stuck in a non-functional state, and even after link comes up again, PIO requests won't work anymore, and a reset of the whole PCIe controller is needed. Therefore we need to prevent sending PIO requests while the link is down.

Signed-off-by: Pali Rohár pali@kernel.org

Reviewed-by: Stefan Roese sr@denx.de

Thanks, Stefan

---

drivers/pci/pci-aardvark.c | 38 +++++++++++++++++++++----------------- 1 file changed, 21 insertions(+), 17 deletions(-)

diff --git a/drivers/pci/pci-aardvark.c b/drivers/pci/pci-aardvark.c index 1eb257ea8b4a..ccaeecaca8e3 100644 --- a/drivers/pci/pci-aardvark.c +++ b/drivers/pci/pci-aardvark.c @@ -177,6 +177,23 @@ static inline uint advk_readl(struct pcie_advk *pcie, uint reg) return readl(pcie->base + reg); }

+/**

• • pcie_advk_link_up() - Check if PCIe link is up or not
• • @pcie: The PCI device to access
• • Return true on link up.
• • Return false on link down.
• */

+static bool pcie_advk_link_up(struct pcie_advk *pcie) +{

• u32 val, ltssm_state;
• val = advk_readl(pcie, ADVK_LMI_PHY_CFG0);
• ltssm_state = (val & ADVK_LMI_PHY_CFG0_LTSSM_MASK) >> ADVK_LMI_PHY_CFG0_LTSSM_SHIFT;
• return ltssm_state >= ADVK_LMI_PHY_CFG0_LTSSM_L0 && ltssm_state < ADVK_LMI_PHY_CFG0_LTSSM_DISABLED;

+}

• /**
  • pcie_advk_addr_valid() - Check for valid bus address

@@ -195,6 +212,10 @@ static bool pcie_advk_addr_valid(struct pcie_advk *pcie, if (busno == 0 && (dev != 0 || func != 0)) return false;

• /* Access to other buses is possible when link is up */
• if (busno != 0 && !pcie_advk_link_up(pcie))

• return false;
  

• /*
  • In PCI-E only a single device (0) can exist on the secondary bus.
  • Beyond the secondary bus, there might be a Switch and anything is

@@ -618,23 +639,6 @@ retry: return ret; }

-/**

• • pcie_advk_link_up() - Check if PCIe link is up or not
• • @pcie: The PCI device to access
• • Return 1 (true) on link up.
• • Return 0 (false) on link down.
• */

-static int pcie_advk_link_up(struct pcie_advk *pcie) -{

• u32 val, ltssm_state;
• val = advk_readl(pcie, ADVK_LMI_PHY_CFG0);
• ltssm_state = (val & ADVK_LMI_PHY_CFG0_LTSSM_MASK) >> ADVK_LMI_PHY_CFG0_LTSSM_SHIFT;
• return ltssm_state >= ADVK_LMI_PHY_CFG0_LTSSM_L0 && ltssm_state < ADVK_LMI_PHY_CFG0_LTSSM_DISABLED;

-}

• /**
  • pcie_advk_wait_for_link() - Wait for link training to be accomplished

Viele Grüße, Stefan Roese