USB: s3c-hsotg: Fix interrupt cleaning code

This commit does the following:
1) clears all pending interrupts before unmasking;
2) clears interrupts as soon as possible to avoid missing
   next coming that may occur during handling;
3) removes ineffective interrupt cleaning code.

Signed-off-by: Anton Tikhomirov <av.tikhomirov@samsung.com>
Reviewed-by: Kyoungil Kim<ki0351.kim@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 20 insertions, 38 deletions

diff --git a/drivers/usb/gadget/s3c-hsotg.c b/drivers/usb/gadget/s3c-hsotg.c
index 7cd597ca162f..d7a279bb51dc 100644
--- a/drivers/usb/gadget/s3c-hsotg.c
+++ b/drivers/usb/gadget/s3c-hsotg.c
@@ -1775,10 +1775,12 @@ static void s3c_hsotg_epint(struct s3c_hsotg *hsotg, unsigned int idx,
         u32 epctl_reg = dir_in ? S3C_DIEPCTL(idx) : S3C_DOEPCTL(idx);
         u32 epsiz_reg = dir_in ? S3C_DIEPTSIZ(idx) : S3C_DOEPTSIZ(idx);
         u32 ints;
-        u32 clear = 0;
 
         ints = readl(hsotg->regs + epint_reg);
 
+        /* Clear endpoint interrupts */
+        writel(ints, hsotg->regs + epint_reg);
+
         dev_dbg(hsotg->dev, "%s: ep%d(%s) DxEPINT=0x%08x\n",
                 __func__, idx, dir_in ? "in" : "out", ints);
 
@@ -1801,19 +1803,13 @@ static void s3c_hsotg_epint(struct s3c_hsotg *hsotg, unsigned int idx,
 
                         s3c_hsotg_handle_outdone(hsotg, idx, false);
                 }
-
-                clear |= S3C_DxEPINT_XferCompl;
         }
 
-        if (ints & S3C_DxEPINT_EPDisbld) {
+        if (ints & S3C_DxEPINT_EPDisbld)
                 dev_dbg(hsotg->dev, "%s: EPDisbld\n", __func__);
-                clear |= S3C_DxEPINT_EPDisbld;
-        }
 
-        if (ints & S3C_DxEPINT_AHBErr) {
+        if (ints & S3C_DxEPINT_AHBErr)
                 dev_dbg(hsotg->dev, "%s: AHBErr\n", __func__);
-                clear |= S3C_DxEPINT_AHBErr;
-        }
 
         if (ints & S3C_DxEPINT_Setup) {  /* Setup or Timeout */
                 dev_dbg(hsotg->dev, "%s: Setup/Timeout\n",  __func__);
@@ -1829,14 +1825,10 @@ static void s3c_hsotg_epint(struct s3c_hsotg *hsotg, unsigned int idx,
                         else
                                 s3c_hsotg_handle_outdone(hsotg, 0, true);
                 }
-
-                clear |= S3C_DxEPINT_Setup;
         }
 
-        if (ints & S3C_DxEPINT_Back2BackSetup) {
+        if (ints & S3C_DxEPINT_Back2BackSetup)
                 dev_dbg(hsotg->dev, "%s: B2BSetup/INEPNakEff\n", __func__);
-                clear |= S3C_DxEPINT_Back2BackSetup;
-        }
 
         if (dir_in) {
                 /* not sure if this is important, but we'll clear it anyway
@@ -1844,14 +1836,12 @@ static void s3c_hsotg_epint(struct s3c_hsotg *hsotg, unsigned int idx,
                 if (ints & S3C_DIEPMSK_INTknTXFEmpMsk) {
                         dev_dbg(hsotg->dev, "%s: ep%d: INTknTXFEmpMsk\n",
                                 __func__, idx);
-                        clear |= S3C_DIEPMSK_INTknTXFEmpMsk;
                 }
 
                 /* this probably means something bad is happening */
                 if (ints & S3C_DIEPMSK_INTknEPMisMsk) {
                         dev_warn(hsotg->dev, "%s: ep%d: INTknEP\n",
                                  __func__, idx);
-                        clear |= S3C_DIEPMSK_INTknEPMisMsk;
                 }
 
                 /* FIFO has space or is empty (see GAHBCFG) */
@@ -1860,11 +1850,8 @@ static void s3c_hsotg_epint(struct s3c_hsotg *hsotg, unsigned int idx,
                         dev_dbg(hsotg->dev, "%s: ep%d: TxFIFOEmpty\n",
                                 __func__, idx);
                         s3c_hsotg_trytx(hsotg, hs_ep);
-                        clear |= S3C_DIEPMSK_TxFIFOEmpty;
                 }
         }
-
-        writel(clear, hsotg->regs + epint_reg);
 }
 
 /**
@@ -2056,7 +2043,6 @@ irq_retry:
                 dev_info(hsotg->dev, "OTGInt: %08x\n", otgint);
 
                 writel(otgint, hsotg->regs + S3C_GOTGINT);
-                writel(S3C_GINTSTS_OTGInt, hsotg->regs + S3C_GINTSTS);
         }
 
         if (gintsts & S3C_GINTSTS_DisconnInt) {
@@ -2072,8 +2058,9 @@ irq_retry:
         }
 
         if (gintsts & S3C_GINTSTS_EnumDone) {
-                s3c_hsotg_irq_enumdone(hsotg);
                 writel(S3C_GINTSTS_EnumDone, hsotg->regs + S3C_GINTSTS);
+
+                s3c_hsotg_irq_enumdone(hsotg);
         }
 
         if (gintsts & S3C_GINTSTS_ConIDStsChng) {
@@ -2101,10 +2088,6 @@ irq_retry:
                         if (daint_in & 1)
                                 s3c_hsotg_epint(hsotg, ep, 1);
                 }
-
-                writel(daint, hsotg->regs + S3C_DAINT);
-                writel(gintsts & (S3C_GINTSTS_OEPInt | S3C_GINTSTS_IEPInt),
-                       hsotg->regs + S3C_GINTSTS);
         }
 
         if (gintsts & S3C_GINTSTS_USBRst) {
@@ -2112,6 +2095,8 @@ irq_retry:
                 dev_dbg(hsotg->dev, "GNPTXSTS=%08x\n",
                         readl(hsotg->regs + S3C_GNPTXSTS));
 
+                writel(S3C_GINTSTS_USBRst, hsotg->regs + S3C_GINTSTS);
+
                 kill_all_requests(hsotg, &hsotg->eps[0], -ECONNRESET, true);
 
                 /* it seems after a reset we can end up with a situation
@@ -2123,8 +2108,6 @@ irq_retry:
                 s3c_hsotg_init_fifo(hsotg);
 
                 s3c_hsotg_enqueue_setup(hsotg);
-
-                writel(S3C_GINTSTS_USBRst, hsotg->regs + S3C_GINTSTS);
         }
 
         /* check both FIFOs */
@@ -2138,8 +2121,6 @@ irq_retry:
 
                 s3c_hsotg_disable_gsint(hsotg, S3C_GINTSTS_NPTxFEmp);
                 s3c_hsotg_irq_fifoempty(hsotg, false);
-
-                writel(S3C_GINTSTS_NPTxFEmp, hsotg->regs + S3C_GINTSTS);
         }
 
         if (gintsts & S3C_GINTSTS_PTxFEmp) {
@@ -2149,8 +2130,6 @@ irq_retry:
 
                 s3c_hsotg_disable_gsint(hsotg, S3C_GINTSTS_PTxFEmp);
                 s3c_hsotg_irq_fifoempty(hsotg, true);
-
-                writel(S3C_GINTSTS_PTxFEmp, hsotg->regs + S3C_GINTSTS);
         }
 
         if (gintsts & S3C_GINTSTS_RxFLvl) {
@@ -2159,7 +2138,6 @@ irq_retry:
                  * set. */
 
                 s3c_hsotg_handle_rx(hsotg);
-                writel(S3C_GINTSTS_RxFLvl, hsotg->regs + S3C_GINTSTS);
         }
 
         if (gintsts & S3C_GINTSTS_ModeMis) {
@@ -2193,19 +2171,17 @@ irq_retry:
         if (gintsts & S3C_GINTSTS_GOUTNakEff) {
                 dev_info(hsotg->dev, "GOUTNakEff triggered\n");
 
-                s3c_hsotg_dump(hsotg);
-
                 writel(S3C_DCTL_CGOUTNak, hsotg->regs + S3C_DCTL);
-                writel(S3C_GINTSTS_GOUTNakEff, hsotg->regs + S3C_GINTSTS);
+
+                s3c_hsotg_dump(hsotg);
         }
 
         if (gintsts & S3C_GINTSTS_GINNakEff) {
                 dev_info(hsotg->dev, "GINNakEff triggered\n");
 
-                s3c_hsotg_dump(hsotg);
-
                 writel(S3C_DCTL_CGNPInNAK, hsotg->regs + S3C_DCTL);
-                writel(S3C_GINTSTS_GINNakEff, hsotg->regs + S3C_GINTSTS);
+
+                s3c_hsotg_dump(hsotg);
         }
 
         /* if we've had fifo events, we should try and go around the
@@ -2585,6 +2561,12 @@ int usb_gadget_probe_driver(struct usb_gadget_driver *driver,
 
         writel(1 << 18 | S3C_DCFG_DevSpd_HS,  hsotg->regs + S3C_DCFG);
 
+        /* Clear any pending OTG interrupts */
+        writel(0xffffffff, hsotg->regs + S3C_GOTGINT);
+
+        /* Clear any pending interrupts */
+        writel(0xffffffff, hsotg->regs + S3C_GINTSTS);
+
         writel(S3C_GINTSTS_DisconnInt | S3C_GINTSTS_SessReqInt |
                S3C_GINTSTS_ConIDStsChng | S3C_GINTSTS_USBRst |
                S3C_GINTSTS_EnumDone | S3C_GINTSTS_OTGInt |