[PATCH 11/13] PCI: brcmstb: Put max_burst_size setting in cfg_data
From: Jim Quinlan
Date: Fri Sep 11 2026 - 19:42:42 EST
Rather than ascertaining the max_burst_size setting by comparing different
SoC IDs, specify the setting in the config_data structure for each SoC.
Also add a comment on each SoC's encoding of this field.
Note: Previously, the max burst setting used for the 4908 Soc was 2.
However, it appears that the setting of 2 is illegal for this chip. Set it
to 0 as (a) this is the safest (smallest) choice and (b) the 2 was probably
interpreted by the HW as a 0 anyway.
Signed-off-by: Jim Quinlan <james.quinlan@xxxxxxxxxxxx>
---
drivers/pci/controller/pcie-brcmstb.c | 29 ++++++++++++---------------
1 file changed, 13 insertions(+), 16 deletions(-)
diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index 047783e33ae4..8bca98e6f5fa 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -317,6 +317,7 @@ struct pcie_cfg_data {
u32 flags;
u32 quirks;
u8 num_inbound_wins;
+ u8 burst_setting;
int (*perst_set)(struct brcm_pcie *pcie, u32 val);
int (*bridge_sw_init_set)(struct brcm_pcie *pcie, u32 val);
int (*post_setup)(struct brcm_pcie *pcie);
@@ -1153,7 +1154,7 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
void __iomem *base = pcie->base;
struct pci_host_bridge *bridge;
struct resource_entry *entry;
- u32 tmp, burst, num_lanes, num_lanes_cap;
+ u32 tmp, num_lanes, num_lanes_cap;
u8 num_out_wins = 0;
int num_inbound_wins = 0;
int memc, ret;
@@ -1188,20 +1189,6 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
/* Wait for SerDes to be stable */
usleep_range(100, 200);
- /*
- * SCB_MAX_BURST_SIZE is a two bit field. For GENERIC chips it
- * is encoded as 0=128, 1=256, 2=512, 3=Rsvd, for BCM7278 it
- * is encoded as 0=Rsvd, 1=128, 2=256, 3=512.
- */
- if (BFLAG(pcie, IS_BMIPS))
- burst = 0x1; /* 256 bytes */
- else if (pcie->cfg->soc_base == BCM2711)
- burst = 0x0; /* 128 bytes */
- else if (pcie->cfg->soc_base == BCM7278)
- burst = 0x3; /* 512 bytes */
- else
- burst = 0x2; /* 512 bytes */
-
/*
* Set SCB_MAX_BURST_SIZE, CFG_READ_UR_MODE, SCB_ACCESS_EN,
* RCB_MPS_MODE, RCB_64B_MODE
@@ -1209,7 +1196,8 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
tmp = readl(base + PCIE_MISC_MISC_CTRL);
u32p_replace_bits(&tmp, 1, PCIE_MISC_MISC_CTRL_SCB_ACCESS_EN_MASK);
u32p_replace_bits(&tmp, 1, PCIE_MISC_MISC_CTRL_CFG_READ_UR_MODE_MASK);
- u32p_replace_bits(&tmp, burst, PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_MASK);
+ u32p_replace_bits(&tmp, pcie->cfg->burst_setting,
+ PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_MASK);
u32p_replace_bits(&tmp, 1, PCIE_MISC_MISC_CTRL_PCIE_RCB_MPS_MODE_MASK);
u32p_replace_bits(&tmp, 1, PCIE_MISC_MISC_CTRL_PCIE_RCB_64B_MODE_MASK);
writel(tmp, base + PCIE_MISC_MISC_CTRL);
@@ -1961,6 +1949,7 @@ static const struct pcie_cfg_data generic_cfg = {
.perst_set = brcm_pcie_perst_set_generic,
.bridge_sw_init_set = brcm_pcie_bridge_sw_init_set_generic,
.num_inbound_wins = 3,
+ .burst_setting = 0x2, /* 0=128B, 1=256B, 2=512B, 3=Rsvd */
};
static const struct pcie_cfg_data bcm2711_cfg = {
@@ -1970,6 +1959,7 @@ static const struct pcie_cfg_data bcm2711_cfg = {
.bridge_sw_init_set = brcm_pcie_bridge_sw_init_set_generic,
.num_inbound_wins = 3,
.quirks = CFG_QUIRK_EARLY_PERST_ASSERT,
+ .burst_setting = 0x0, /* 0=128B, 1=256B, 2=512B, 3=Rsvd */
};
static const struct pcie_cfg_data bcm2712_cfg = {
@@ -1981,6 +1971,7 @@ static const struct pcie_cfg_data bcm2712_cfg = {
.quirks = CFG_QUIRK_AVOID_BRIDGE_SHUTDOWN |
CFG_QUIRK_NO_RGR1_TIMER,
.num_inbound_wins = 10,
+ .burst_setting = 0x2, /* 0=64B, 1=128B, 2=256B, 3=Rsvd */
};
static const struct pcie_cfg_data bcm4908_cfg = {
@@ -1990,6 +1981,7 @@ static const struct pcie_cfg_data bcm4908_cfg = {
.bridge_sw_init_set = brcm_pcie_bridge_sw_init_set_generic,
.num_inbound_wins = 3,
.quirks = CFG_QUIRK_PERST_PCIE_REV_CUTOFF,
+ .burst_setting = 0x0, /* 0=64B, 1=128B, 2=Rsvd, 3=Rsvd */
};
static const struct pcie_cfg_data bcm7278_cfg = {
@@ -1998,6 +1990,7 @@ static const struct pcie_cfg_data bcm7278_cfg = {
.perst_set = brcm_pcie_perst_set_7278,
.bridge_sw_init_set = brcm_pcie_bridge_sw_init_set_7278,
.num_inbound_wins = 3,
+ .burst_setting = 0x3, /* 0=Resv, 1=128B, 2=256B, 3=512B */
};
static const struct pcie_cfg_data bcm7425_cfg = {
@@ -2009,6 +2002,7 @@ static const struct pcie_cfg_data bcm7425_cfg = {
.quirks = CFG_QUIRK_OB_WIN_32BIT_ADDR
| CFG_QUIRK_OB_WIN_MAXSZ_128MB | CFG_QUIRK_32BIT_PCI_OPS,
.flags = CFG_FLG_IS_BMIPS,
+ .burst_setting = 1, /* 0=128B, 1=256B, 2=Rsvd, 3=Rsvd */
};
static const struct pcie_cfg_data bcm7435_cfg = {
@@ -2020,6 +2014,7 @@ static const struct pcie_cfg_data bcm7435_cfg = {
.quirks = CFG_QUIRK_OB_WIN_32BIT_ADDR
| CFG_QUIRK_OB_WIN_MAXSZ_128MB,
.flags = CFG_FLG_IS_BMIPS,
+ .burst_setting = 1, /* 0=128B, 1=256B, 2=Rsvd, 3=Rsvd */
};
static const struct pcie_cfg_data bcm7216_cfg = {
@@ -2029,6 +2024,7 @@ static const struct pcie_cfg_data bcm7216_cfg = {
.bridge_sw_init_set = brcm_pcie_bridge_sw_init_set_7278,
.flags = CFG_FLG_HAS_PHY | CFG_FLG_HAS_ERR_REPORT,
.num_inbound_wins = 3,
+ .burst_setting = 0x3, /* 0=Resv, 1=128B, 2=256B, 3=512B */
};
static const struct pcie_cfg_data bcm7712_cfg = {
@@ -2038,6 +2034,7 @@ static const struct pcie_cfg_data bcm7712_cfg = {
.soc_base = BCM7712,
.num_inbound_wins = 10,
.quirks = CFG_QUIRK_NO_RGR1_TIMER,
+ .burst_setting = 0x2, /* 0=64B, 1=128B, 2=256B, 3=Resv */
};
static const struct of_device_id brcm_pcie_match[] = {
--
2.34.1