From: Sergio Paracuellos sergio.paracuellos@gmail.com
commit 7d761b084b3c785e1fbbe707fbdf7baba905c6ad upstream.
When nothing is connected to pcie ports, each port is set to reset state. When this occurs, next access result in a hang on boot as follows:
mt7621-pci 1e140000.pcie: pcie0 no card, disable it (RST & CLK) mt7621-pci 1e140000.pcie: pcie1 no card, disable it (RST & CLK) mt7621-pci 1e140000.pcie: pcie2 no card, disable it (RST & CLK) [ HANGS HERE ]
Fix this just detecting 'nothing is connected state' to avoid next accesses to pcie port related configuration registers.
Fixes: b99cc3a2b6b6 ("staging: mt7621-pci: avoid custom 'map_irq' function") Cc: stable stable@vger.kernel.org Reported-by: DENG Qingfang dqfext@gmail.com Signed-off-by: Sergio Paracuellos sergio.paracuellos@gmail.com Link: https://lore.kernel.org/r/20210823170803.2108-1-sergio.paracuellos@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/staging/mt7621-pci/pci-mt7621.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
--- a/drivers/staging/mt7621-pci/pci-mt7621.c +++ b/drivers/staging/mt7621-pci/pci-mt7621.c @@ -56,6 +56,7 @@ #define PCIE_BAR_ENABLE BIT(0) #define PCIE_PORT_INT_EN(x) BIT(20 + (x)) #define PCIE_PORT_LINKUP BIT(0) +#define PCIE_PORT_CNT 3
#define PERST_DELAY_MS 100
@@ -388,10 +389,11 @@ static void mt7621_pcie_reset_ep_deasser msleep(PERST_DELAY_MS); }
-static void mt7621_pcie_init_ports(struct mt7621_pcie *pcie) +static int mt7621_pcie_init_ports(struct mt7621_pcie *pcie) { struct device *dev = pcie->dev; struct mt7621_pcie_port *port, *tmp; + u8 num_disabled = 0; int err;
mt7621_pcie_reset_assert(pcie); @@ -423,6 +425,7 @@ static void mt7621_pcie_init_ports(struc slot); mt7621_control_assert(port); port->enabled = false; + num_disabled++;
if (slot == 0) { tmp = port; @@ -433,6 +436,8 @@ static void mt7621_pcie_init_ports(struc phy_power_off(tmp->phy); } } + + return (num_disabled != PCIE_PORT_CNT) ? 0 : -ENODEV; }
static void mt7621_pcie_enable_port(struct mt7621_pcie_port *port) @@ -540,7 +545,11 @@ static int mt7621_pci_probe(struct platf return err; }
- mt7621_pcie_init_ports(pcie); + err = mt7621_pcie_init_ports(pcie); + if (err) { + dev_err(dev, "Nothing connected in virtual bridges\n"); + return 0; + }
err = mt7621_pcie_enable_ports(bridge); if (err) {