platform: nvadsp: Fix ADSP watchdog handler

The following Fixes have been done :
1) The nvadsp_os_start API waits for on comeplete object. Hence, it should not
be directly called from the interrupt context. Moving the API call to a
workqueue which is scheduled from watchdog interrupt handler.

2) The ADSP driver allows only a maximum of 2 crashes to occur. This is done in
order to make sure that adsp driver does not keep on restarting recursively.

Bug 200020631

Change-Id: I1d946c326f57f999d423c4cf4ec008ae62ffe948
Signed-off-by: Ajay Nandakumar <anandakumarm@nvidia.com>
Reviewed-on: http://git-master/r/455595
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Nitin Kumbhar <nkumbhar@nvidia.com>

diff --git a/drivers/platform/tegra/nvadsp/os.c b/drivers/platform/tegra/nvadsp/os.c
index f1fd8b143828f05f222372485214293a532f3edc..6094cb7f5b1f3fa51e1c69d8a2e802865f5130a9 100644 (file)
--- a/drivers/platform/tegra/nvadsp/os.c
+++ b/drivers/platform/tegra/nvadsp/os.c
@@ -98,6 +98,9 @@
  */
 #define ADSP_CLK_FIX_RATE (APE_CLK_FIX_RATE * ADSP_TO_APE_CLK_RATIO)
 
+/* total number of crashes allowed on adsp */
+#define ALLOWED_CRASHES        2
+
 struct nvadsp_debug_log {
        struct device *dev;
        char *debug_ram_rdr;
@@ -107,13 +110,15 @@ struct nvadsp_debug_log {
 
 struct nvadsp_os_data {
 #if !CONFIG_SYSTEM_FPGA
-       void __iomem *reset_reg;
+       void __iomem            *reset_reg;
 #endif
-       struct platform_device *pdev;
-       struct global_sym_info *adsp_glo_sym_tbl;
-       void __iomem *misc_base;
-       struct resource **dram_region;
-       struct nvadsp_debug_log logger;
+       struct platform_device  *pdev;
+       struct global_sym_info  *adsp_glo_sym_tbl;
+       void __iomem            *misc_base;
+       struct resource         **dram_region;
+       struct nvadsp_debug_log logger;
+       struct work_struct      restart_os_work;
+       int                     adsp_num_crashes;
 };
 
 static struct nvadsp_os_data priv;
@@ -726,24 +731,44 @@ int nvadsp_os_start(void)
 EXPORT_SYMBOL(nvadsp_os_start);
 
 
-static  irqreturn_t adsp_wdt_handler(int irq, void *arg)
+static void nvadsp_os_restart(struct work_struct *work)
 {
-       struct device *dev = arg;
-       dev_crit(dev, "ADSP OS crashed .... Restarting ADSP OS\n");
-#if CONFIG_SYSTEM_FPGA
+       struct nvadsp_os_data *data =
+               container_of(work, struct nvadsp_os_data, restart_os_work);
+       struct device *dev = &data->pdev->dev;
+
+       data->adsp_num_crashes++;
+       if (data->adsp_num_crashes >= ALLOWED_CRASHES) {
+               /* making pdev NULL so that externally start is not called */
+               priv.pdev = NULL;
+               dev_crit(dev, "ADSP has crashed too many times\n");
+               return;
+       }
+
        if (nvadsp_os_start())
                dev_crit(dev, "Unable to restart ADSP OS\n");
+}
+
+static irqreturn_t adsp_wdt_handler(int irq, void *arg)
+{
+       struct nvadsp_os_data *data = arg;
+       struct device *dev = &data->pdev->dev;
+#if CONFIG_SYSTEM_FPGA
+       dev_crit(dev, "ADSP OS Hanged or Crashed! Restarting...\n");
+       schedule_work(&data->restart_os_work);
+#else
+       dev_crit(dev, "ADSP OS Hanged or Crashed!\n");
 #endif
        return 0;
 }
 
 int nvadsp_os_probe(struct platform_device *pdev)
 {
-
        struct nvadsp_drv_data *drv_data = platform_get_drvdata(pdev);
-       int virq = tegra_agic_irq_get_virq(INT_ADSP_WDT);
+       int wdt_virq = tegra_agic_irq_get_virq(INT_ADSP_WDT);
        struct device *dev = &pdev->dev;
        int ret = 0;
+
 #if !CONFIG_SYSTEM_FPGA
        priv.reset_reg = ioremap(APE_FPGA_MISC_RST_DEVICES, 1);
        if (!priv.reset_reg) {
@@ -762,13 +787,15 @@ int nvadsp_os_probe(struct platform_device *pdev)
                        "unable to create adsp debug logger file\n");
 #endif
 
-       ret = request_irq(virq, adsp_wdt_handler,
-                       IRQF_TRIGGER_RISING, "adsp watchdog", dev);
-       if (ret)
+       ret = request_irq(wdt_virq, adsp_wdt_handler,
+                       IRQF_TRIGGER_RISING, "adsp watchdog", &priv);
+       if (ret) {
                dev_err(dev, "failed to get adsp watchdog interrupt\n");
+               goto end;
+       }
+
+       INIT_WORK(&priv.restart_os_work, nvadsp_os_restart);
 
-#if !CONFIG_SYSTEM_FPGA
 end:
-#endif
        return ret;
 }