Problem statement:
Due to hardware errata in Aero controllers, reads to certain
fusion registers could intermittently return zero.
This behavior is transient in nature and subsequent reads will return
valid value.
Fix:
For Aero controllers, any calls to readl to read from certain registers,
will be retried for maximum three times, if read returns zero.
Signed-off-by: Shivasharan S <shivasharan.srikanteshwara@xxxxxxxxxxxx>
---
drivers/scsi/megaraid/megaraid_sas_base.c | 39 +++++++++++++++++++++++------
drivers/scsi/megaraid/megaraid_sas_fusion.c | 28 +++++++++++++--------
2 files changed, 49 insertions(+), 18 deletions(-)
diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index 1d2272fddc5f..d4e3df320a0c 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -220,6 +220,28 @@ megasas_free_ctrl_dma_buffers(struct megasas_instance *instance);
static inline void
megasas_init_ctrl_params(struct megasas_instance *instance);
+u32 megasas_readl(struct megasas_instance *instance,
+ const volatile void __iomem *addr)
+{
+ u32 i = 0, ret_val;
+ /*
+ * Due to a HW errata in Aero controllers, reads to certain
+ * Fusion registers could intermittently return all zeroes.
+ * This behavior is transient in nature and subsequent reads will
+ * return valid value. As a workaround in driver, retry readl for
+ * upto three times until a non-zero value is read.
+ */
+ if (instance->adapter_type == AERO_SERIES) {
+ do {
+ ret_val = readl(addr);
+ i++;
+ } while (ret_val == 0 && i < 3);
+ return ret_val;
+ } else {
+ return readl(addr);
+ }
+}
+
/**
* megasas_set_dma_settings - Populate DMA address, length and flags for DCMDs
* @instance: Adapter soft state
@@ -3842,7 +3864,8 @@ megasas_transition_to_ready(struct megasas_instance *instance, int ocr)
if (instance->adapter_type != MFI_SERIES) {
for (i = 0; i < (10 * 1000); i += 20) {
- if (readl(
+ if (megasas_readl(
+ instance,
&instance->
reg_set->
doorbell) & 1)
@@ -5401,7 +5424,8 @@ static int megasas_init_fw(struct megasas_instance *instance)
if (instance->adapter_type >= VENTURA_SERIES) {
scratch_pad_2 =
- readl(&instance->reg_set->outbound_scratch_pad_2);
+ megasas_readl(instance,
+ &instance->reg_set->outbound_scratch_pad_2);
instance->max_raid_mapsize = ((scratch_pad_2 >>
MR_MAX_RAID_MAP_SIZE_OFFSET_SHIFT) &
MR_MAX_RAID_MAP_SIZE_MASK);
@@ -5413,8 +5437,8 @@ static int megasas_init_fw(struct megasas_instance *instance)
if (msix_enable && !msix_disable) {
int irq_flags = PCI_IRQ_MSIX;
- scratch_pad_1 = readl
- (&instance->reg_set->outbound_scratch_pad_1);
+ scratch_pad_1 = megasas_readl
+ (instance, &instance->reg_set->outbound_scratch_pad_1);
/* Check max MSI-X vectors */
if (fusion) {
if (instance->adapter_type == THUNDERBOLT_SERIES) {
@@ -5525,7 +5549,8 @@ static int megasas_init_fw(struct megasas_instance *instance)
if (instance->adapter_type >= VENTURA_SERIES) {
scratch_pad_3 =
- readl(&instance->reg_set->outbound_scratch_pad_3);
+ megasas_readl(instance,
+ &instance->reg_set->outbound_scratch_pad_3);
if ((scratch_pad_3 & MR_NVME_PAGE_SIZE_MASK) >=
MR_DEFAULT_NVME_PAGE_SHIFT)
instance->nvme_page_size =
@@ -6193,8 +6218,8 @@ megasas_set_dma_mask(struct megasas_instance *instance)
* If 32 bit DMA mask fails, then try for 64 bit mask
* for FW capable of handling 64 bit DMA.
*/
- scratch_pad_1 = readl
- (&instance->reg_set->outbound_scratch_pad_1);
+ scratch_pad_1 = megasas_readl
+ (instance, &instance->reg_set->outbound_scratch_pad_1);
if (!(scratch_pad_1 & MR_CAN_HANDLE_64_BIT_DMA_OFFSET))
goto fail_set_dma_mask;
diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c b/drivers/scsi/megaraid/megaraid_sas_fusion.c
index e4c3edc73099..50e2ed865041 100644
--- a/drivers/scsi/megaraid/megaraid_sas_fusion.c
+++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c
@@ -95,6 +95,8 @@ static void megasas_free_reply_fusion(struct megasas_instance *instance);
static inline
void megasas_configure_queue_sizes(struct megasas_instance *instance);
static void megasas_fusion_crash_dump(struct megasas_instance *instance);
+extern u32 megasas_readl(struct megasas_instance *instance,
+ const volatile void __iomem *addr);
/**
* megasas_check_same_4gb_region - check if allocation
@@ -267,7 +269,8 @@ megasas_fusion_update_can_queue(struct megasas_instance *instance, int fw_boot_c
/* ventura FW does not fill outbound_scratch_pad_2 with queue depth */
if (instance->adapter_type < VENTURA_SERIES)
cur_max_fw_cmds =
- readl(&instance->reg_set->outbound_scratch_pad_2) & 0x00FFFF;
+ megasas_readl(instance,
+ &instance->reg_set->outbound_scratch_pad_2) & 0x00FFFF;
if (dual_qdepth_disable || !cur_max_fw_cmds)
cur_max_fw_cmds = instance->instancet->read_fw_status_reg(instance) & 0x00FFFF;
@@ -984,8 +987,8 @@ megasas_ioc_init_fusion(struct megasas_instance *instance)
cmd = fusion->ioc_init_cmd;
- scratch_pad_1 = readl
- (&instance->reg_set->outbound_scratch_pad_1);
+ scratch_pad_1 = megasas_readl
+ (instance, &instance->reg_set->outbound_scratch_pad_1);
cur_rdpq_mode = (scratch_pad_1 & MR_RDPQ_MODE_OFFSET) ? 1 : 0;
@@ -1104,7 +1107,7 @@ megasas_ioc_init_fusion(struct megasas_instance *instance)
instance->instancet->disable_intr(instance);
for (i = 0; i < (10 * 1000); i += 20) {
- if (readl(&instance->reg_set->doorbell) & 1)
+ if (megasas_readl(instance, &instance->reg_set->doorbell) & 1)
msleep(20);
else
break;
@@ -1653,7 +1656,8 @@ megasas_init_adapter_fusion(struct megasas_instance *instance)
megasas_configure_queue_sizes(instance);
- scratch_pad_1 = readl(&instance->reg_set->outbound_scratch_pad_1);
+ scratch_pad_1 = megasas_readl(instance,
+ &instance->reg_set->outbound_scratch_pad_1);
/* If scratch_pad_1 & MEGASAS_MAX_CHAIN_SIZE_UNITS_MASK is set,
* Firmware support extended IO chain frame which is 4 times more than
* legacy Firmware.
@@ -3731,7 +3735,7 @@ megasas_release_fusion(struct megasas_instance *instance)
static u32
megasas_read_fw_status_reg_fusion(struct megasas_instance *instance)
{
- return readl(&instance->reg_set->outbound_scratch_pad_0);
+ return megasas_readl(instance, &instance->reg_set->outbound_scratch_pad_0);
}
/**
@@ -3793,11 +3797,12 @@ megasas_adp_reset_fusion(struct megasas_instance *instance,
writel(MPI2_WRSEQ_6TH_KEY_VALUE, &instance->reg_set->fusion_seq_offset);
/* Check that the diag write enable (DRWE) bit is on */
- host_diag = readl(&instance->reg_set->fusion_host_diag);
+ host_diag = megasas_readl(instance, &instance->reg_set->fusion_host_diag);
retry = 0;
while (!(host_diag & HOST_DIAG_WRITE_ENABLE)) {
msleep(100);
- host_diag = readl(&instance->reg_set->fusion_host_diag);
+ host_diag = megasas_readl(instance,
+ &instance->reg_set->fusion_host_diag);
if (retry++ == 100) {
dev_warn(&instance->pdev->dev,
"Host diag unlock failed from %s %d\n",
@@ -3814,11 +3819,12 @@ megasas_adp_reset_fusion(struct megasas_instance *instance,
msleep(3000);
/* Make sure reset adapter bit is cleared */
- host_diag = readl(&instance->reg_set->fusion_host_diag);
+ host_diag = megasas_readl(instance, &instance->reg_set->fusion_host_diag);
retry = 0;
while (host_diag & HOST_DIAG_RESET_ADAPTER) {
msleep(100);
- host_diag = readl(&instance->reg_set->fusion_host_diag);
+ host_diag = megasas_readl(instance,
+ &instance->reg_set->fusion_host_diag);
if (retry++ == 1000) {
dev_warn(&instance->pdev->dev,
"Diag reset adapter never cleared %s %d\n",
@@ -4607,7 +4613,7 @@ int megasas_reset_fusion(struct Scsi_Host *shost, int reason)
dev_info(&instance->pdev->dev, "IO/DCMD timeout is detected, "
"forcibly FAULT Firmware\n");
atomic_set(&instance->adprecovery, MEGASAS_ADPRESET_SM_INFAULT);
- status_reg = readl(&instance->reg_set->doorbell);
+ status_reg = megasas_readl(instance, &instance->reg_set->doorbell);
writel(status_reg | MFI_STATE_FORCE_OCR,
&instance->reg_set->doorbell);
readl(&instance->reg_set->doorbell);
--
2.16.1
