[PATCH 11/11] scsi: hisi_sas: workaround a v3 hw hilink bug

From: John Garry
Date: Wed May 02 2018 - 11:58:12 EST


From: Xiaofei Tan <tanxiaofei@xxxxxxxxxx>

There is an SoC bug of v3 hw development version. When hot-
unplugging a directly attached disk, the PHY down interrupt
may not happen. It is very easy to appear on some boards.

When this issue occurs, the controller will receive many invalid
dword frames, and the "alos" fields of register HILINK_ERR_DFX
can indicate that disk was unplugged.

As an workaround solution, this patch detects this issue in
the channel interrupt, and workaround it by following steps:
- Disable the PHY
- Clear error code and interrupt
- Enable the PHY

Then the HW will reissue PHY down interrupt.

Signed-off-by: Xiaofei Tan <tanxiaofei@xxxxxxxxxx>
Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
---
drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 25 ++++++++++++++++++++++++-
1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index 28bb71e..492c3be 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -106,6 +106,7 @@
#define COMPL_Q_0_RD_PTR 0x4f0
#define AWQOS_AWCACHE_CFG 0xc84
#define ARQOS_ARCACHE_CFG 0xc88
+#define HILINK_ERR_DFX 0xe04

/* phy registers requiring init */
#define PORT_BASE (0x2000)
@@ -167,6 +168,7 @@
#define CHL_INT1_DMAC_RX_AXI_RD_ERR_OFF 22
#define CHL_INT2 (PORT_BASE + 0x1bc)
#define CHL_INT2_SL_IDAF_TOUT_CONF_OFF 0
+#define CHL_INT2_RX_INVLD_DW_OFF 30
#define CHL_INT2_STP_LINK_TIMEOUT_OFF 31
#define CHL_INT0_MSK (PORT_BASE + 0x1c0)
#define CHL_INT1_MSK (PORT_BASE + 0x1c4)
@@ -1345,6 +1347,7 @@ static irqreturn_t int_chnl_int_v3_hw(int irq_no, void *p)
{
struct hisi_hba *hisi_hba = p;
struct device *dev = hisi_hba->dev;
+ struct pci_dev *pci_dev = hisi_hba->pci_dev;
u32 irq_msk;
int phy_no = 0;

@@ -1410,8 +1413,28 @@ static irqreturn_t int_chnl_int_v3_hw(int irq_no, void *p)

hisi_sas_phy_write32(hisi_hba, phy_no,
CHL_INT2, irq_value2);
- }

+ if ((irq_value2 & BIT(CHL_INT2_RX_INVLD_DW_OFF)) &&
+ (pci_dev->revision == 0x20)) {
+ u32 reg_value;
+ int rc;
+
+ rc = hisi_sas_read32_poll_timeout_atomic(
+ HILINK_ERR_DFX, reg_value,
+ !((reg_value >> 8) & BIT(phy_no)),
+ 1000, 10000);
+ if (rc) {
+ disable_phy_v3_hw(hisi_hba, phy_no);
+ hisi_sas_phy_write32(hisi_hba, phy_no,
+ CHL_INT2,
+ BIT(CHL_INT2_RX_INVLD_DW_OFF));
+ hisi_sas_phy_read32(hisi_hba, phy_no,
+ ERR_CNT_INVLD_DW);
+ mdelay(1);
+ enable_phy_v3_hw(hisi_hba, phy_no);
+ }
+ }
+ }

if (irq_msk & (2 << (phy_no * 4)) && irq_value0) {
hisi_sas_phy_write32(hisi_hba, phy_no,
--
1.9.1