[Qemu-devel] [PATCH 05/12] usb-ehci: improve mmio tracing

[Gerd Hoffmann <kraxel@redhat.com>]

Add a separate tracepoint to log how register values change in response
to a mmio write.  Especially useful for registers which have read-only
or clear-on-write bits in them.

No change in behavior.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/usb-ehci.c |   16 ++++++----------
 trace-events  |    3 ++-
 2 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/hw/usb-ehci.c b/hw/usb-ehci.c
index 85e5ed9..b9204ab 100644
--- a/hw/usb-ehci.c
+++ b/hw/usb-ehci.c
@@ -719,10 +719,6 @@ static void handle_port_status_write(EHCIState *s, int port, uint32_t val)
     int rwc;
     USBDevice *dev = s->ports[port].dev;
 
-    DPRINTF("port_status_write: "
-            "PORTSC (port %d) curr %08X new %08X rw-clear %08X rw %08X\n",
-            port, *portsc, val, (val & PORTSC_RWC_MASK), val & PORTSC_RO_MASK);
-
     rwc = val & PORTSC_RWC_MASK;
     val &= PORTSC_RO_MASK;
 
@@ -744,8 +740,6 @@ static void handle_port_status_write(EHCIState *s, int port, uint32_t val)
         }
 
         if (s->ports[port].dev) {
-            DPRINTF("port_status_write: "
-                    "Device was connected before reset, clearing CSC bit\n");
             *portsc &= ~PORTSC_CSC;
         }
 
@@ -760,16 +754,16 @@ static void handle_port_status_write(EHCIState *s, int port, uint32_t val)
 
     *portsc &= ~PORTSC_RO_MASK;
     *portsc |= val;
-    DPRINTF("port_status_write: Port %d status set to 0x%08x\n", port, *portsc);
 }
 
 static void ehci_mem_writel(void *ptr, target_phys_addr_t addr, uint32_t val)
 {
     EHCIState *s = ptr;
+    uint32_t *mmio = (uint32_t *)(&s->mmio[addr]);
+    uint32_t old = *mmio;
     int i;
 
-    trace_usb_ehci_mmio_writel(addr, addr2str(addr), val,
-                               *(uint32_t *)(&s->mmio[addr]));
+    trace_usb_ehci_mmio_writel(addr, addr2str(addr), val);
 
     /* Only aligned reads are allowed on OHCI */
     if (addr & 3) {
@@ -780,6 +774,7 @@ static void ehci_mem_writel(void *ptr, target_phys_addr_t addr, uint32_t val)
 
     if (addr >= PORTSC && addr < PORTSC + 4 * NB_PORTS) {
         handle_port_status_write(s, (addr-PORTSC)/4, val);
+        trace_usb_ehci_mmio_change(addr, addr2str(addr), *mmio, old);
         return;
     }
 
@@ -858,7 +853,8 @@ static void ehci_mem_writel(void *ptr, target_phys_addr_t addr, uint32_t val)
         break;
     }
 
-    *(uint32_t *)(&s->mmio[addr]) = val;
+    *mmio = val;
+    trace_usb_ehci_mmio_change(addr, addr2str(addr), *mmio, old);
 }
 
 
diff --git a/trace-events b/trace-events
index 22f93c7..b2ccd07 100644
--- a/trace-events
+++ b/trace-events
@@ -197,7 +197,8 @@ disable sun4m_iommu_bad_addr(uint64_t addr) "bad addr %"PRIx64""
 # hw/usb-ehci.c
 disable usb_ehci_reset(void) "=== RESET ==="
 disable usb_ehci_mmio_readl(uint32_t addr, const char *str, uint32_t val) "rd mmio %04x [%s] = %x"
-disable usb_ehci_mmio_writel(uint32_t addr, const char *str, uint32_t val, uint32_t oldval) "wr mmio %04x [%s] = %x (old: %x)"
+disable usb_ehci_mmio_writel(uint32_t addr, const char *str, uint32_t val) "wr mmio %04x [%s] = %x"
+disable usb_ehci_mmio_change(uint32_t addr, const char *str, uint32_t new, uint32_t old) "ch mmio %04x [%s] = %x (old: %x)"
 disable usb_ehci_usbsts(const char *sts, int state) "usbsts %s %d"
 disable usb_ehci_state(const char *schedule, const char *state) "%s schedule %s"
 disable usb_ehci_qh(uint32_t addr, uint32_t next, uint32_t c_qtd, uint32_t n_qtd, uint32_t a_qtd, int rl, int mplen, int eps, int ep, int devaddr, int c, int h, int dtc, int i) "QH @ %08x: next %08x qtds %08x,%08x,%08x - rl %d, mplen %d, eps %d, ep %d, dev %d, c %d, h %d, dtc %d, i %d"
-- 
1.7.1