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>

diff --git a/drivers/usb/gadget/s3c-hsotg.c b/drivers/usb/gadget/s3c-hsotg.c
index 7cd597ca162f1b5818ab0c6b78299a61914b1549..d7a279bb51dc2e159917d4912e07cf00d2f8a647 100644 (file)
--- 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 |