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Re: [PATCH] bc47xx : fix ssb irq setup

To: linux-mips@linux-mips.org, Ralf Baechle <ralf@linux-mips.org>
Subject: Re: [PATCH] bc47xx : fix ssb irq setup
From: matthieu castet <castet.matthieu@free.fr>
Date: Tue, 30 Jun 2009 23:10:56 +0200
Cc: Florian Fainelli <florian@openwrt.org>, Michael Buesch <mb@bu3sch.de>
In-reply-to: <4A4A7DF7.2010209@free.fr>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <4A4A7DF7.2010209@free.fr>
Sender: linux-mips-bounce@linux-mips.org
User-agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.19) Gecko/20081204 Iceape/1.1.14 (Debian-1.1.14-1)
Update : the previous patch was broken by my mailler

the current ssb irq setup (in ssb_mipscore_init) have some problem :
it configure some device on some irq without checking that the irq is not taken by an other device.

For example in my case PCI host is on irq 0 and IPSEC on irq 3.
The current code :
- store in dev->irq that IPSEC irq is 3+2
- do a set_irq 0->3 on PCI host

But now IPSEC irq is not routed anymore to the mips code and dev->irq is wrong.
This cause problem described in [1].

This patch try to solve the problem by making set_irq configure the device we want to take the irq on the shared irq0. The previous example become :
- store in dev->irq that IPSEC irq is 3+2
- do a set_irq 0->3 on PCI host :
- irq 3 is already taken by IPSEC. do a set_irq 3->0 on IPSEC


I also added some code to print the irq configuration after irq setup to allow 
easier
debugging. And I add extra checking in ssb_mips_irq to report device without irq or device with not routed irq.


[1] http://www.danm.de/files/src/bcm5365p/REPORTED_DEVICES

Signed-off-by: Matthieu CASTET <castet.matthieu@free.fr>
Acked-by : Michael Buesch <mb@bu3sch.de>
Tested-by: Florian Fainelli <florian@openwrt.org>

Index: linux-2.6/drivers/ssb/driver_mipscore.c
===================================================================
--- linux-2.6.orig/drivers/ssb/driver_mipscore.c        2009-06-19 
22:31:31.000000000 +0200
+++ linux-2.6/drivers/ssb/driver_mipscore.c     2009-06-30 22:28:11.000000000 
+0200
@@ -49,29 +49,54 @@

static inline u32 ssb_irqflag(struct ssb_device *dev)
{
-       return ssb_read32(dev, SSB_TPSFLAG) & SSB_TPSFLAG_BPFLAG;
+       u32 tpsflag = ssb_read32(dev, SSB_TPSFLAG);
+       if (tpsflag)
+               return ssb_read32(dev, SSB_TPSFLAG) & SSB_TPSFLAG_BPFLAG;
+       else
+               /* not irq supported */
+               return 0x3f;
+}
+
+static struct ssb_device *find_device(struct ssb_device *rdev, int irqflag)
+{
+       struct ssb_bus *bus = rdev->bus;
+       int i;
+       for (i = 0; i < bus->nr_devices; i++) {
+               struct ssb_device *dev;
+               dev = &(bus->devices[i]);
+               if (ssb_irqflag(dev) == irqflag)
+                       return dev;
+       }
+       return NULL;
}

/* Get the MIPS IRQ assignment for a specified device.
 * If unassigned, 0 is returned.
+ * If disabled, 5 is returned.
+ * If not supported, 6 is returned.
 */
unsigned int ssb_mips_irq(struct ssb_device *dev)
{
        struct ssb_bus *bus = dev->bus;
+       struct ssb_device *mdev = bus->mipscore.dev;
        u32 irqflag;
        u32 ipsflag;
        u32 tmp;
        unsigned int irq;

        irqflag = ssb_irqflag(dev);
+       if (irqflag == 0x3f)
+               return 6;
        ipsflag = ssb_read32(bus->mipscore.dev, SSB_IPSFLAG);
        for (irq = 1; irq <= 4; irq++) {
                tmp = ((ipsflag & ipsflag_irq_mask[irq]) >> 
ipsflag_irq_shift[irq]);
                if (tmp == irqflag)
                        break;
        }
-       if (irq == 5)
-               irq = 0;
+       if (irq == 5) {
+               if ((1 << irqflag) & ssb_read32(mdev, SSB_INTVEC))
+                       irq = 0;
+       }

        return irq;
}
@@ -97,25 +122,56 @@
        struct ssb_device *mdev = bus->mipscore.dev;
        u32 irqflag = ssb_irqflag(dev);

+       BUG_ON(oldirq == 6);
+
        dev->irq = irq + 2;

-       ssb_dprintk(KERN_INFO PFX
-                   "set_irq: core 0x%04x, irq %d => %d\n",
-                   dev->id.coreid, oldirq, irq);
        /* clear the old irq */
        if (oldirq == 0)
                ssb_write32(mdev, SSB_INTVEC, (~(1 << irqflag) & 
ssb_read32(mdev, SSB_INTVEC)));
-       else
+       else if (oldirq != 5)
                clear_irq(bus, oldirq);

        /* assign the new one */
        if (irq == 0) {
                ssb_write32(mdev, SSB_INTVEC, ((1 << irqflag) | 
ssb_read32(mdev, SSB_INTVEC)));
        } else {
+               u32 ipsflag = ssb_read32(mdev, SSB_IPSFLAG);
+               if ((ipsflag & ipsflag_irq_mask[irq]) != ipsflag_irq_mask[irq]) 
{
+                       u32 oldipsflag = (ipsflag & ipsflag_irq_mask[irq]) >> 
ipsflag_irq_shift[irq];
+                       struct ssb_device *olddev = find_device(dev, 
oldipsflag);
+                       if (olddev)
+                               set_irq(olddev, 0);
+               }
                irqflag <<= ipsflag_irq_shift[irq];
-               irqflag |= (ssb_read32(mdev, SSB_IPSFLAG) & 
~ipsflag_irq_mask[irq]);
+               irqflag |= (ipsflag & ~ipsflag_irq_mask[irq]);
                ssb_write32(mdev, SSB_IPSFLAG, irqflag);
        }
+       ssb_dprintk(KERN_INFO PFX
+                   "set_irq: core 0x%04x, irq %d => %d\n",
+                   dev->id.coreid, oldirq+2, irq+2);
+}
+
+static void print_irq(struct ssb_device *dev, unsigned int irq)
+{
+       int i;
+       static const char *irq_name[] = {"2(S)", "3", "4", "5", "6", "D", "I"};
+       ssb_dprintk(KERN_INFO PFX
+               "core 0x%04x, irq :", dev->id.coreid);
+       for (i = 0; i <= 6; i++) {
+               ssb_dprintk(" %s%s", irq_name[i], i==irq?"*":" ");
+       }
+       ssb_dprintk("\n");
+}
+
+static void dump_irq(struct ssb_bus *bus)
+{
+       int i;
+       for (i = 0; i < bus->nr_devices; i++) {
+               struct ssb_device *dev;
+               dev = &(bus->devices[i]);
+               print_irq(dev, ssb_mips_irq(dev));
+       }
}

static void ssb_mips_serial_init(struct ssb_mipscore *mcore)
@@ -197,16 +253,23 @@

        /* Assign IRQs to all cores on the bus, start with irq line 2, because 
serial usually takes 1 */
        for (irq = 2, i = 0; i < bus->nr_devices; i++) {
+               int mips_irq;
                dev = &(bus->devices[i]);
-               dev->irq = ssb_mips_irq(dev) + 2;
+               mips_irq = ssb_mips_irq(dev);
+               if (mips_irq > 4)
+                       dev->irq = 0;
+               else
+                       dev->irq = mips_irq + 2;
+               if (dev->irq > 5)
+                       continue;
                switch (dev->id.coreid) {
                case SSB_DEV_USB11_HOST:
                        /* shouldn't need a separate irq line for non-4710, 
most of them have a proper
                         * external usb controller on the pci */
                        if ((bus->chip_id == 0x4710) && (irq <= 4)) {
                                set_irq(dev, irq++);
-                               break;
                        }
+                       break;
                        /* fallthrough */
                case SSB_DEV_PCI:
                case SSB_DEV_ETHERNET:
@@ -220,6 +283,8 @@
                        }
                }
        }
+       ssb_dprintk(KERN_INFO PFX "after irq reconfiguration\n");
+       dump_irq(bus);

        ssb_mips_serial_init(mcore);
        ssb_mips_flash_detect(mcore);

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