[PATCH] PCIe: SPEAr13xx: fix dw_pcie_cfg_read/write() usage

From: Pratyush Anand
Date: Mon Sep 07 2015 - 00:11:53 EST


dw_pcie_cfg_read/write() expects 1st argument 'addr' as a 32 bit word
aligned address, 2nd argument 'where' as the offset within that word(0, 1,
2 or 3) and 3rd argument 'size' is the number of bytes need to be read at
the offset(could be 1, 2 ,4).

SPEAr13xx is using dw_pcie_cfg_read() and dw_pcie_cfg_write() incorrectly.
Without this fix, SPEAr13xx host will never work with few buggy gen1 card
which connects with only gen1 host and also with any endpoint which would
generate a read request of more than 128 bytes.

Cc: stable@xxxxxxxxxxxxxxx # v3.17+
Signed-off-by: Pratyush Anand <panand@xxxxxxxxxx>
Reported-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
drivers/pci/host/pcie-spear13xx.c | 26 ++++++++++++++------------
1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/pci/host/pcie-spear13xx.c b/drivers/pci/host/pcie-spear13xx.c
index c49fbdc0f6e4..40862681f010 100644
--- a/drivers/pci/host/pcie-spear13xx.c
+++ b/drivers/pci/host/pcie-spear13xx.c
@@ -163,34 +163,36 @@ static int spear13xx_pcie_establish_link(struct pcie_port *pp)
* default value in capability register is 512 bytes. So force
* it to 128 here.
*/
- dw_pcie_cfg_read(pp->dbi_base, exp_cap_off + PCI_EXP_DEVCTL, 4, &val);
+ dw_pcie_cfg_read(pp->dbi_base + exp_cap_off + PCI_EXP_DEVCTL,
+ 0, 2, &val);
val &= ~PCI_EXP_DEVCTL_READRQ;
- dw_pcie_cfg_write(pp->dbi_base, exp_cap_off + PCI_EXP_DEVCTL, 4, val);
+ dw_pcie_cfg_write(pp->dbi_base + exp_cap_off + PCI_EXP_DEVCTL,
+ 0, 2, val);

- dw_pcie_cfg_write(pp->dbi_base, PCI_VENDOR_ID, 2, 0x104A);
- dw_pcie_cfg_write(pp->dbi_base, PCI_DEVICE_ID, 2, 0xCD80);
+ dw_pcie_cfg_write(pp->dbi_base + PCI_VENDOR_ID, 0, 2, 0x104A);
+ dw_pcie_cfg_write(pp->dbi_base + PCI_VENDOR_ID, 2, 2, 0xCD80);

/*
* if is_gen1 is set then handle it, so that some buggy card
* also works
*/
if (spear13xx_pcie->is_gen1) {
- dw_pcie_cfg_read(pp->dbi_base, exp_cap_off + PCI_EXP_LNKCAP, 4,
- &val);
+ dw_pcie_cfg_read(pp->dbi_base + exp_cap_off + PCI_EXP_LNKCAP,
+ 0, 4, &val);
if ((val & PCI_EXP_LNKCAP_SLS) != PCI_EXP_LNKCAP_SLS_2_5GB) {
val &= ~((u32)PCI_EXP_LNKCAP_SLS);
val |= PCI_EXP_LNKCAP_SLS_2_5GB;
- dw_pcie_cfg_write(pp->dbi_base, exp_cap_off +
- PCI_EXP_LNKCAP, 4, val);
+ dw_pcie_cfg_write(pp->dbi_base + exp_cap_off +
+ PCI_EXP_LNKCAP, 0, 4, val);
}

- dw_pcie_cfg_read(pp->dbi_base, exp_cap_off + PCI_EXP_LNKCTL2, 4,
- &val);
+ dw_pcie_cfg_read(pp->dbi_base + exp_cap_off + PCI_EXP_LNKCTL2,
+ 0, 2, &val);
if ((val & PCI_EXP_LNKCAP_SLS) != PCI_EXP_LNKCAP_SLS_2_5GB) {
val &= ~((u32)PCI_EXP_LNKCAP_SLS);
val |= PCI_EXP_LNKCAP_SLS_2_5GB;
- dw_pcie_cfg_write(pp->dbi_base, exp_cap_off +
- PCI_EXP_LNKCTL2, 4, val);
+ dw_pcie_cfg_write(pp->dbi_base + exp_cap_off +
+ PCI_EXP_LNKCTL2, 0, 2, val);
}
}

--
2.5.0

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