On Thu, Jul 25, 2019 at 12:49:27AM +0000, Lei Wang wrote: > New driver supports error detection and correction on the devices with ARM > DMC-520 memory controller. > > Signed-off-by: Lei Wang <leiwang_git@xxxxxxxxxxx> > Reviewed-by: James Morse <james.morse@xxxxxxx> > --- > Changes in v5: > - When enable configured interrupts, do not potentially disable > other irrelevant interrupts. > - fix return type of dmc520_get_scrub_type to enum scrub_type > - Use capital letters for enum > - Retrieve memory width from dmc register format_control > - use cheaper spin_lock API. > - Remove compatible line for "brcm,dmc-520" > - Add James' Reviewed-by > --- > MAINTAINERS | 6 + > drivers/edac/Kconfig | 7 + > drivers/edac/Makefile | 1 + > drivers/edac/dmc520_edac.c | 632 +++++++++++++++++++++++++++++++++++++ > 4 files changed, 646 insertions(+) > create mode 100644 drivers/edac/dmc520_edac.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 77eae44bf5de..7c1ac8bc8ea1 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -5703,6 +5703,12 @@ F: Documentation/driver-api/edac.rst > F: drivers/edac/ > F: include/linux/edac.h > > +EDAC-DMC520 > +M: Lei Wang <lewan@xxxxxxxxxxxxx> > +L: linux-edac@xxxxxxxxxxxxxxx > +S: Supported > +F: drivers/edac/dmc520_edac.c > + > EDAC-E752X > M: Mark Gross <mark.gross@xxxxxxxxx> > L: linux-edac@xxxxxxxxxxxxxxx > diff --git a/drivers/edac/Kconfig b/drivers/edac/Kconfig > index 200c04ce5b0e..7fde5aea0c1a 100644 > --- a/drivers/edac/Kconfig > +++ b/drivers/edac/Kconfig > @@ -510,4 +510,11 @@ config EDAC_ASPEED > First, ECC must be configured in the bootloader. Then, this driver > will expose error counters via the EDAC kernel framework. > > +config EDAC_DMC520 > + tristate "ARM DMC-520 ECC" > + depends on ARM64 > + help > + Support for error detection and correction on the > + SoCs with ARM DMC-520 DRAM controller. > + > endif # EDAC > diff --git a/drivers/edac/Makefile b/drivers/edac/Makefile > index 165ca65e1a3a..e0d98f5b2045 100644 > --- a/drivers/edac/Makefile > +++ b/drivers/edac/Makefile > @@ -85,3 +85,4 @@ obj-$(CONFIG_EDAC_XGENE) += xgene_edac.o > obj-$(CONFIG_EDAC_TI) += ti_edac.o > obj-$(CONFIG_EDAC_QCOM) += qcom_edac.o > obj-$(CONFIG_EDAC_ASPEED) += aspeed_edac.o > +obj-$(CONFIG_EDAC_DMC520) += dmc520_edac.o > diff --git a/drivers/edac/dmc520_edac.c b/drivers/edac/dmc520_edac.c > new file mode 100644 > index 000000000000..aeb8d84405cf > --- /dev/null > +++ b/drivers/edac/dmc520_edac.c > @@ -0,0 +1,632 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* EDAC driver for DMC-520 */ That comment is kinda useless. > +#include <linux/bitfield.h> > +#include <linux/edac.h> > +#include <linux/interrupt.h> > +#include <linux/io.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/platform_device.h> > +#include <linux/spinlock.h> > +#include "edac_mc.h" > + > +/* DMC-520 registers */ > +#define REG_OFFSET_FEATURE_CONFIG 0x130 > +#define REG_OFFSET_ECC_ERRC_COUNT_31_00 0x158 > +#define REG_OFFSET_ECC_ERRC_COUNT_63_32 0x15C > +#define REG_OFFSET_ECC_ERRD_COUNT_31_00 0x160 > +#define REG_OFFSET_ECC_ERRD_COUNT_63_32 0x164 > +#define REG_OFFSET_INTERRUPT_CONTROL 0x500 > +#define REG_OFFSET_INTERRUPT_CLR 0x508 > +#define REG_OFFSET_INTERRUPT_STATUS 0x510 > +#define REG_OFFSET_DRAM_ECC_ERRC_INT_INFO_31_00 0x528 > +#define REG_OFFSET_DRAM_ECC_ERRC_INT_INFO_63_32 0x52C > +#define REG_OFFSET_DRAM_ECC_ERRD_INT_INFO_31_00 0x530 > +#define REG_OFFSET_DRAM_ECC_ERRD_INT_INFO_63_32 0x534 > +#define REG_OFFSET_ADDRESS_CONTROL_NOW 0x1010 > +#define REG_OFFSET_MEMORY_TYPE_NOW 0x1128 > +#define REG_OFFSET_SCRUB_CONTROL0_NOW 0x1170 > +#define REG_OFFSET_FORMAT_CONTROL 0x18 > + > +/* DMC-520 types, masks and bitfields */ > +#define DRAM_ECC_INT_CE_BIT BIT(2) > +#define DRAM_ECC_INT_UE_BIT BIT(3) > +#define ALL_INT_MASK GENMASK(9, 0) > +#define MEMORY_WIDTH_MASK GENMASK(1, 0) > +#define SCRUB_TRIGGER0_NEXT_MASK GENMASK(1, 0) > +#define REG_FIELD_DRAM_ECC_ENABLED GENMASK(1, 0) > +#define REG_FIELD_MEMORY_TYPE GENMASK(2, 0) > +#define REG_FIELD_DEVICE_WIDTH GENMASK(9, 8) > +#define REG_FIELD_ADDRESS_CONTROL_COL GENMASK(2, 0) > +#define REG_FIELD_ADDRESS_CONTROL_ROW GENMASK(10, 8) > +#define REG_FIELD_ADDRESS_CONTROL_BANK GENMASK(18, 16) > +#define REG_FIELD_ADDRESS_CONTROL_RANK GENMASK(25, 24) > +#define REG_FIELD_ERR_INFO_LOW_VALID BIT(0) > +#define REG_FIELD_ERR_INFO_LOW_COL GENMASK(10, 1) > +#define REG_FIELD_ERR_INFO_LOW_ROW GENMASK(28, 11) > +#define REG_FIELD_ERR_INFO_LOW_RANK GENMASK(31, 29) > +#define REG_FIELD_ERR_INFO_HIGH_BANK GENMASK(3, 0) > +#define REG_FIELD_ERR_INFO_HIGH_VALID BIT(31) > + > +#define DRAM_ADDRESS_CONTROL_MIN_COL_BITS 8 > +#define DRAM_ADDRESS_CONTROL_MIN_ROW_BITS 11 > + > +#define DMC520_SCRUB_TRIGGER_ERR_DETECT 2 > +#define DMC520_SCRUB_TRIGGER_IDLE 3 One tab too many. Keep them all vertically aligned. > + > +/* Driver settings */ > +/* The max-length message would be: "rank:7 bank:15 row:262143 col:1023". > + * Max length is 34. Using a 40-size buffer is enough. > + */ > +#define EDAC_MSG_BUF_SIZE 40 That define is driver-local only. Prefix it with "DMC520_" or so, not with "EDAC_". > +#define EDAC_MOD_NAME "dmc520-edac" > +#define EDAC_CTL_NAME "dmc520" > + > +/* the data bus width for the attached memory chips. */ > +enum dmc520_mem_width { > + MEM_WIDTH_X32 = 2, > + MEM_WIDTH_X64 = 3 > +}; > + > +/* memory type */ > +enum dmc520_mem_type { > + MEM_TYPE_DDR3 = 1, > + MEM_TYPE_DDR4 = 2 > +}; > + > +/* memory device width */ > +enum dmc520_dev_width { > + DEV_WIDTH_X4 = 0, > + DEV_WIDTH_X8 = 1, > + DEV_WIDTH_X16 = 2 > +}; > + > +struct ecc_error_info { > + u32 col; > + u32 row; > + u32 bank; > + u32 rank; > +}; > + > +/* The EDAC driver private data */ > +struct dmc520_edac { > + void __iomem *reg_base; > + u32 nintr; > + u32 interrupt_mask_all; > + spinlock_t ecc_lock; > + u32 interrupt_masks[0]; > +}; > + > +static int dmc520_mc_idx; > + > +static irqreturn_t > +dmc520_edac_dram_all_isr(int irq, struct mem_ctl_info *mci, u32 interrupt_mask); > + > +#define DECLARE_ISR(index) \ > +static irqreturn_t dmc520_isr_##index (int irq, void *data) \ Please integrate scripts/checkpatch.pl into your patch creation workflow. Some of the warnings/errors *actually* make sense. WARNING: space prohibited between function name and open parenthesis '(' #200: FILE: drivers/edac/dmc520_edac.c:108: +static irqreturn_t dmc520_isr_##index (int irq, void *data) \ > +{ \ > + struct mem_ctl_info *mci; \ > + struct dmc520_edac *edac; \ > + mci = data; \ > + edac = mci->pvt_info; \ > + return dmc520_edac_dram_all_isr(irq, mci, edac->interrupt_masks[index]); \ > +} > + > +DECLARE_ISR(0) > +DECLARE_ISR(1) > +/* More DECLARE_ISR(index) can be added to support more interrupt lines. */ > + > +irq_handler_t dmc520_isr_array[] = { > + dmc520_isr_0, > + dmc520_isr_1 > + /* More dmc520_isr_index can be added to support more interrupt lines. */ What are those comments really for? > +}; > + > +static u32 dmc520_read_reg(struct dmc520_edac *edac, u32 offset) > +{ > + return readl(edac->reg_base + offset); > +} > + > +static void dmc520_write_reg(struct dmc520_edac *edac, u32 val, u32 offset) > +{ > + writel(val, edac->reg_base + offset); > +} > + > +static u32 dmc520_calc_dram_ecc_error(u32 value) > +{ > + u32 total = 0; > + > + /* Each rank's error counter takes one byte */ > + while (value > 0) { > + total += (value & 0xFF); > + value >>= 8; > + } > + return total; > +} > + > +static u32 dmc520_get_dram_ecc_error_count(struct dmc520_edac *edac, > + bool is_ce) > +{ > + u32 reg_offset_low, reg_offset_high; > + u32 err_low, err_high; > + u32 err_count; > + > + reg_offset_low = is_ce ? REG_OFFSET_ECC_ERRC_COUNT_31_00 : > + REG_OFFSET_ECC_ERRD_COUNT_31_00; > + reg_offset_high = is_ce ? REG_OFFSET_ECC_ERRC_COUNT_63_32 : > + REG_OFFSET_ECC_ERRD_COUNT_63_32; > + > + err_low = dmc520_read_reg(edac, reg_offset_low); > + err_high = dmc520_read_reg(edac, reg_offset_high); > + /* Reset error counters */ > + dmc520_write_reg(edac, 0, reg_offset_low); > + dmc520_write_reg(edac, 0, reg_offset_high); > + > + err_count = dmc520_calc_dram_ecc_error(err_low) + > + dmc520_calc_dram_ecc_error(err_high); > + > + return err_count; > +} > + > +static void dmc520_get_dram_ecc_error_info(struct dmc520_edac *edac, > + bool is_ce, > + struct ecc_error_info *info) > +{ > + u32 reg_offset_low, reg_offset_high; > + u32 reg_val_low, reg_val_high; > + bool valid; > + > + reg_offset_low = is_ce ? REG_OFFSET_DRAM_ECC_ERRC_INT_INFO_31_00 : > + REG_OFFSET_DRAM_ECC_ERRD_INT_INFO_31_00; > + reg_offset_high = is_ce ? REG_OFFSET_DRAM_ECC_ERRC_INT_INFO_63_32 : > + REG_OFFSET_DRAM_ECC_ERRD_INT_INFO_63_32; > + > + reg_val_low = dmc520_read_reg(edac, reg_offset_low); > + reg_val_high = dmc520_read_reg(edac, reg_offset_high); > + > + valid = (FIELD_GET(REG_FIELD_ERR_INFO_LOW_VALID, reg_val_low) != 0) && > + (FIELD_GET(REG_FIELD_ERR_INFO_HIGH_VALID, reg_val_high) != 0); > + > + if (valid) { > + info->col = FIELD_GET(REG_FIELD_ERR_INFO_LOW_COL, reg_val_low); > + info->row = FIELD_GET(REG_FIELD_ERR_INFO_LOW_ROW, reg_val_low); > + info->rank = FIELD_GET(REG_FIELD_ERR_INFO_LOW_RANK, reg_val_low); > + info->bank = FIELD_GET(REG_FIELD_ERR_INFO_HIGH_BANK, reg_val_high); > + } else { > + memset(info, 0, sizeof(struct ecc_error_info)); > + } > +} > + > +static bool dmc520_is_ecc_enabled(void __iomem *reg_base) > +{ > + u32 reg_val = readl(reg_base + REG_OFFSET_FEATURE_CONFIG); > + > + return (FIELD_GET(REG_FIELD_DRAM_ECC_ENABLED, reg_val) != 0); No need for that " != 0" at the end. > +} > + > +static enum scrub_type dmc520_get_scrub_type(struct dmc520_edac *edac) > +{ > + enum scrub_type type = SCRUB_NONE; > + u32 reg_val, scrub_cfg; > + > + reg_val = dmc520_read_reg(edac, REG_OFFSET_SCRUB_CONTROL0_NOW); > + scrub_cfg = FIELD_GET(SCRUB_TRIGGER0_NEXT_MASK, reg_val); > + > + if (DMC520_SCRUB_TRIGGER_ERR_DETECT == scrub_cfg || > + DMC520_SCRUB_TRIGGER_IDLE == scrub_cfg) > + type = SCRUB_HW_PROG; More from checkpatch: WARNING: Comparisons should place the constant on the right side of the test #309: FILE: drivers/edac/dmc520_edac.c:217: + if (DMC520_SCRUB_TRIGGER_ERR_DETECT == scrub_cfg || WARNING: Comparisons should place the constant on the right side of the test #310: FILE: drivers/edac/dmc520_edac.c:218: + DMC520_SCRUB_TRIGGER_IDLE == scrub_cfg) > + > + return type; > +} > + > +/* Get the memory data bus width, in number of bytes. */ > +static u32 dmc520_get_memory_width(struct dmc520_edac *edac) > +{ > + static u32 mem_width; > + u32 reg_val; > + enum dmc520_mem_width mem_width_field; Please sort function local variables declaration in a reverse christmas tree order: <type A> longest_variable_name; <type B> shorter_var_name; <type C> even_shorter; <type D> i; Here and in the other functions. > + > + if (mem_width == 0) { Flip that check and save yourself an indentation level: if (mem_width) return; reg_val = ... > + reg_val = dmc520_read_reg(edac, REG_OFFSET_FORMAT_CONTROL); > + mem_width_field = FIELD_GET(MEMORY_WIDTH_MASK, reg_val); > + > + if (mem_width_field == MEM_WIDTH_X32) > + mem_width = 4; /* 32-bits, 4 bytes */ > + else if (mem_width_field == MEM_WIDTH_X64) > + mem_width = 8; /* 64-bits, 8 bytes */ Please no side-comments. And those you can directly remove as they're useless - your defines and variables should be named properly so that there is no need for a comment here additionally. > + } > + > + return mem_width; > +} > + > +static enum mem_type dmc520_get_mtype(struct dmc520_edac *edac) > +{ > + enum mem_type mt = MEM_UNKNOWN; > + u32 reg_val; > + enum dmc520_mem_type type; > + > + reg_val = dmc520_read_reg(edac, REG_OFFSET_MEMORY_TYPE_NOW); > + type = FIELD_GET(REG_FIELD_MEMORY_TYPE, reg_val); > + > + switch (type) { > + case MEM_TYPE_DDR3: > + mt = MEM_DDR3; > + break; > + > + case MEM_TYPE_DDR4: > + mt = MEM_DDR4; > + break; > + } > + > + return mt; > +} > + > +static enum dev_type dmc520_get_dtype(struct dmc520_edac *edac) > +{ > + enum dev_type dt = DEV_UNKNOWN; > + u32 reg_val; > + enum dmc520_dev_width device_width; > + > + reg_val = dmc520_read_reg(edac, REG_OFFSET_MEMORY_TYPE_NOW); > + device_width = FIELD_GET(REG_FIELD_DEVICE_WIDTH, reg_val); > + > + switch (device_width) { > + case DEV_WIDTH_X4: > + dt = DEV_X4; > + break; > + > + case DEV_WIDTH_X8: > + dt = DEV_X8; > + break; > + > + case DEV_WIDTH_X16: > + dt = DEV_X16; > + break; > + } > + > + return dt; > +} > + > +static u32 dmc520_get_rank_count(void __iomem *reg_base) > +{ > + u32 reg_val, rank_bits; > + > + reg_val = readl(reg_base + REG_OFFSET_ADDRESS_CONTROL_NOW); > + rank_bits = FIELD_GET(REG_FIELD_ADDRESS_CONTROL_RANK, reg_val); > + > + return (1 << rank_bits); return BIT(rank_bits); > +} > + > +static u64 dmc520_get_rank_size(struct dmc520_edac *edac) > +{ > + u32 reg_val, col_bits, row_bits, bank_bits; > + > + reg_val = dmc520_read_reg(edac, REG_OFFSET_ADDRESS_CONTROL_NOW); > + > + col_bits = FIELD_GET(REG_FIELD_ADDRESS_CONTROL_COL, reg_val) + > + DRAM_ADDRESS_CONTROL_MIN_COL_BITS; > + row_bits = FIELD_GET(REG_FIELD_ADDRESS_CONTROL_ROW, reg_val) + > + DRAM_ADDRESS_CONTROL_MIN_ROW_BITS; > + bank_bits = FIELD_GET(REG_FIELD_ADDRESS_CONTROL_BANK, reg_val); > + > + return (u64)dmc520_get_memory_width(edac) << (col_bits + row_bits + bank_bits); > +} > + > +static void dmc520_handle_dram_ecc_errors(struct mem_ctl_info *mci, > + bool is_ce) > +{ > + struct ecc_error_info info; > + struct dmc520_edac *edac; > + u32 cnt; > + char message[EDAC_MSG_BUF_SIZE]; > + > + edac = mci->pvt_info; > + dmc520_get_dram_ecc_error_info(edac, is_ce, &info); > + > + cnt = dmc520_get_dram_ecc_error_count(edac, is_ce); > + > + if (cnt > 0) { Save an indentation level: if (!cnt) return; snprintf... > + snprintf(message, ARRAY_SIZE(message), > + "rank:%d bank:%d row:%d col:%d", > + info.rank, info.bank, > + info.row, info.col); > + > + spin_lock(&edac->ecc_lock); > + edac_mc_handle_error((is_ce ? HW_EVENT_ERR_CORRECTED : > + HW_EVENT_ERR_UNCORRECTED), > + mci, cnt, 0, 0, 0, info.rank, -1, -1, > + message, ""); > + spin_unlock(&edac->ecc_lock); > + } > +} > + > +static irqreturn_t dmc520_edac_dram_ecc_isr(int irq, struct mem_ctl_info *mci, bool is_ce) > +{ > + u32 i_mask; > + struct dmc520_edac *edac; > + > + edac = mci->pvt_info; > + > + i_mask = is_ce ? DRAM_ECC_INT_CE_BIT : DRAM_ECC_INT_UE_BIT; > + > + dmc520_handle_dram_ecc_errors(mci, is_ce); > + > + dmc520_write_reg(edac, i_mask, REG_OFFSET_INTERRUPT_CLR); > + > + return IRQ_HANDLED; > +} > + > +static irqreturn_t > +dmc520_edac_dram_all_isr(int irq, struct mem_ctl_info *mci, u32 interrupt_mask) > +{ > + struct dmc520_edac *edac; > + u32 status; > + irqreturn_t irq_ret = IRQ_NONE; > + > + edac = mci->pvt_info; > + > + status = dmc520_read_reg(edac, REG_OFFSET_INTERRUPT_STATUS); > + > + if ((interrupt_mask & DRAM_ECC_INT_CE_BIT) && > + (status & DRAM_ECC_INT_CE_BIT)) > + irq_ret = dmc520_edac_dram_ecc_isr(irq, mci, true); > + > + if ((interrupt_mask & DRAM_ECC_INT_UE_BIT) && > + (status & DRAM_ECC_INT_UE_BIT)) > + irq_ret = dmc520_edac_dram_ecc_isr(irq, mci, false); > + > + /* If in the future there are more supported interrupts in a different > + * platform, more condition statements can be added here for each > + * interrupt flag, together with its corresponding isr implementations. > + */ This comment above is useless. Also, kernel comments style is: /* * A sentence ending with a full-stop. * Another sentence. ... * More sentences. ... */ > + > + return irq_ret; > +} > + > +static void dmc520_init_csrow(struct mem_ctl_info *mci) > +{ > + struct csrow_info *csi; > + struct dimm_info *dimm; > + int row, ch; > + enum dev_type dt; > + enum mem_type mt; > + u64 rs; > + u32 pages_per_rank; > + struct dmc520_edac *edac = mci->pvt_info; > + > + dt = dmc520_get_dtype(edac); > + mt = dmc520_get_mtype(edac); > + rs = dmc520_get_rank_size(edac); > + pages_per_rank = rs >> PAGE_SHIFT; > + > + for (row = 0; row < mci->nr_csrows; row++) { > + csi = mci->csrows[row]; > + > + for (ch = 0; ch < csi->nr_channels; ch++) { > + dimm = csi->channels[ch]->dimm; > + dimm->grain = dmc520_get_memory_width(edac); > + dimm->dtype = dt; > + dimm->mtype = mt; > + dimm->edac_mode = EDAC_FLAG_SECDED; > + dimm->nr_pages = pages_per_rank / csi->nr_channels; > + } > + } > +} > + > +static int dmc520_edac_probe(struct platform_device *pdev) > +{ > + struct device *dev; > + struct dmc520_edac *edac; > + struct mem_ctl_info *mci; > + struct edac_mc_layer layers[1]; > + int ret, intr_index, nintr, nintr_registered = 0; > + struct resource *res; > + void __iomem *reg_base; > + u32 reg_val; > + > + /* Parsing the device node */ > + dev = &pdev->dev; > + > + nintr = of_property_count_u32_elems(dev->of_node, "interrupt-config"); > + if (nintr <= 0) { > + edac_printk(KERN_ERR, EDAC_MOD_NAME, > + "Invalid device node configuration: at least one interrupt " > + "line & config is expected.\n"); More from checkpatch: WARNING: quoted string split across lines #528: FILE: drivers/edac/dmc520_edac.c:436: + "Invalid device node configuration: at least one interrupt " + "line & config is expected.\n"); WARNING: quoted string split across lines #535: FILE: drivers/edac/dmc520_edac.c:443: + "Invalid device node configuration: # of interrupt config " + "elements (%d) can not exceed %ld.\n", WARNING: quoted string split across lines #579: FILE: drivers/edac/dmc520_edac.c:487: + "interrupt-config error: " + "element %d's interrupt mask %d has overlap.\n", WARNING: quoted string split across lines #590: FILE: drivers/edac/dmc520_edac.c:498: + "interrupt-config warning: " + "interrupt mask (0x%x) is not supported by dmc520 (0x%lx).\n", > + return -EINVAL; > + } > + > + if (nintr > ARRAY_SIZE(dmc520_isr_array)) { > + edac_printk(KERN_ERR, EDAC_MOD_NAME, > + "Invalid device node configuration: # of interrupt config " > + "elements (%d) can not exceed %ld.\n", > + nintr, ARRAY_SIZE(dmc520_isr_array)); > + return -EINVAL; > + } > + > + /* Initialize dmc520 edac */ > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + reg_base = devm_ioremap_resource(dev, res); > + if (IS_ERR(reg_base)) > + return PTR_ERR(reg_base); > + > + if (!dmc520_is_ecc_enabled(reg_base)) > + return -ENXIO; > + > + layers[0].type = EDAC_MC_LAYER_CHIP_SELECT; > + layers[0].size = dmc520_get_rank_count(reg_base); > + layers[0].is_virt_csrow = true; > + > + mci = edac_mc_alloc(dmc520_mc_idx++, ARRAY_SIZE(layers), layers, > + sizeof(struct dmc520_edac) + sizeof(u32) * nintr); > + if (!mci) { > + edac_printk(KERN_ERR, EDAC_MOD_NAME, > + "Failed to allocate memory for mc instance\n"); > + return -ENOMEM; > + } > + > + edac = mci->pvt_info; > + edac->reg_base = reg_base; > + edac->nintr = nintr; > + edac->interrupt_mask_all = 0; > + spin_lock_init(&edac->ecc_lock); Move that checking... > + > + ret = of_property_read_u32_array(dev->of_node, "interrupt-config", > + edac->interrupt_masks, nintr); > + if (ret) { > + edac_printk(KERN_ERR, EDAC_MOD_NAME, > + "Failed to get interrupt-config arrays.\n"); > + goto err_free_mc; > + } > + > + for (intr_index = 0; intr_index < nintr; ++intr_index) { > + if (edac->interrupt_mask_all & edac->interrupt_masks[intr_index]) { > + edac_printk(KERN_ERR, EDAC_MC, > + "interrupt-config error: " > + "element %d's interrupt mask %d has overlap.\n", > + intr_index, edac->interrupt_masks[intr_index]); > + goto err_free_mc; > + } > + > + edac->interrupt_mask_all |= edac->interrupt_masks[intr_index]; > + } > + > + if ((edac->interrupt_mask_all | ALL_INT_MASK) != ALL_INT_MASK) { > + edac_printk(KERN_WARNING, EDAC_MOD_NAME, > + "interrupt-config warning: " > + "interrupt mask (0x%x) is not supported by dmc520 (0x%lx).\n", > + edac->interrupt_mask_all, ALL_INT_MASK); > + } > + edac->interrupt_mask_all &= ALL_INT_MASK; > + > + platform_set_drvdata(pdev, mci); ... up-to-here before the edac_mc_alloc() call so that you don't have to needlessly goto err_free_mc and free the memory you just allocated if any of those properties reading fails. IOW, do all your hw init first and then call edac_mc_alloc(), when you have everything needed. > + > + mci->pdev = dev; > + mci->mtype_cap = MEM_FLAG_DDR3 | MEM_FLAG_DDR4; > + mci->edac_ctl_cap = EDAC_FLAG_NONE | EDAC_FLAG_SECDED; > + mci->edac_cap = EDAC_FLAG_SECDED; > + mci->scrub_cap = SCRUB_FLAG_HW_SRC; > + mci->scrub_mode = dmc520_get_scrub_type(edac); > + mci->ctl_name = EDAC_CTL_NAME; > + mci->dev_name = dev_name(mci->pdev); > + mci->mod_name = EDAC_MOD_NAME; > + mci->ctl_page_to_phys = NULL; > + > + edac_op_state = EDAC_OPSTATE_INT; > + > + dmc520_init_csrow(mci); > + > + ret = edac_mc_add_mc(mci); > + if (ret) { > + edac_printk(KERN_ERR, EDAC_MOD_NAME, > + "Failed to register with EDAC core\n"); > + goto err_free_mc; > + } > + > + /* Clear interrupts, not affecting other unrelated interrupts */ > + reg_val = dmc520_read_reg(edac, REG_OFFSET_INTERRUPT_CONTROL); > + dmc520_write_reg(edac, reg_val & (~(edac->interrupt_mask_all)), > + REG_OFFSET_INTERRUPT_CONTROL); > + dmc520_write_reg(edac, edac->interrupt_mask_all, > + REG_OFFSET_INTERRUPT_CLR); > + > + for (intr_index = 0; intr_index < nintr; ++intr_index) { > + int irq_id = platform_get_irq(pdev, intr_index); > + > + if (irq_id < 0) { > + edac_printk(KERN_ERR, EDAC_MC, > + "Failed to get irq #%d\n", intr_index); > + ret = -ENODEV; > + goto err_free_irq; > + } > + > + ret = devm_request_irq(&pdev->dev, irq_id, > + dmc520_isr_array[intr_index], IRQF_SHARED, > + dev_name(&pdev->dev), mci); > + if (ret < 0) { > + edac_printk(KERN_ERR, EDAC_MC, > + "Failed to request irq %d\n", irq_id); > + goto err_free_irq; > + } > + > + ++nintr_registered; > + } The same with this IRQ requesting and you'll save yourself the err_free_irq too. > + > + /* Reset DRAM CE/UE counters */ > + if (edac->interrupt_mask_all & DRAM_ECC_INT_CE_BIT) > + dmc520_get_dram_ecc_error_count(edac, true); > + > + if (edac->interrupt_mask_all & DRAM_ECC_INT_UE_BIT) > + dmc520_get_dram_ecc_error_count(edac, false); > + > + /* Enable interrupts, not affecting other unrelated interrupts */ > + dmc520_write_reg(edac, > + reg_val | edac->interrupt_mask_all, > + REG_OFFSET_INTERRUPT_CONTROL); Align at opening brace: dmc520_write_reg(edac, reg_val | edac->interrupt_mask_all, REG_OFFSET_INTERRUPT_CONTROL); > + > + return 0; > + > +err_free_irq: > + for (intr_index = 0; intr_index < nintr_registered; ++intr_index) { > + int irq_id = platform_get_irq(pdev, intr_index); > + > + devm_free_irq(&pdev->dev, irq_id, mci); > + } > + edac_mc_del_mc(&pdev->dev); > +err_free_mc: > + edac_mc_free(mci); > + > + return ret; > +} > + > +static int dmc520_edac_remove(struct platform_device *pdev) > +{ > + struct dmc520_edac *edac; > + struct mem_ctl_info *mci; > + u32 reg_val, intr_index; > + > + mci = platform_get_drvdata(pdev); > + edac = mci->pvt_info; > + > + /* Disable interrupts */ > + reg_val = dmc520_read_reg(edac, REG_OFFSET_INTERRUPT_CONTROL); > + dmc520_write_reg(edac, reg_val & (~(edac->interrupt_mask_all)), > + REG_OFFSET_INTERRUPT_CONTROL); > + > + /* free irq's */ > + for (intr_index = 0; intr_index < edac->nintr; ++intr_index) { > + int irq_id = platform_get_irq(pdev, intr_index); > + > + devm_free_irq(&pdev->dev, irq_id, mci); > + } > + > + edac_mc_del_mc(&pdev->dev); > + edac_mc_free(mci); > + > + return 0; > +} > + > +static const struct of_device_id dmc520_edac_driver_id[] = { > + { .compatible = "arm,dmc-520", }, > + { /* end of table */ } > +}; > + > +MODULE_DEVICE_TABLE(of, dmc520_edac_driver_id); > + > +static struct platform_driver dmc520_edac_driver = { > + .driver = { > + .name = "dmc520", > + .of_match_table = dmc520_edac_driver_id, > + }, > + > + .probe = dmc520_edac_probe, > + .remove = dmc520_edac_remove > +}; > + > +module_platform_driver(dmc520_edac_driver); > + > +MODULE_AUTHOR( No linebreaks like that - let it stick out over 80 cols. > + "Rui Zhao <ruizhao@xxxxxxxxxxxxx>, Lei Wang <lewan@xxxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("DMC-520 ECC driver"); > +MODULE_LICENSE("GPL v2"); > -- Thx. -- Regards/Gruss, Boris. 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