Re: [Intel-gfx] [PATCH v8 06/16] mei: gsc: use polling instead of interrupts
On 9/7/2022 8:58 AM, Tomas Winkler wrote:
A work-around for a HW issue in XEHPSDV that manifests itself when SW reads
a gsc register when gsc is sending an interrupt. The work-around is
to disable interrupts and to use polling instead.
Cc: James Ausmus
Signed-off-by: Vitaly Lubart
Signed-off-by: Tomas Winkler
Signed-off-by: Alexander Usyskin
The only changes from the previously reviewed rev are extra comments and
doc. Those look good, so my r-b stands:
Reviewed-by: Daniele Ceraolo Spurio
Daniele
---
drivers/misc/mei/gsc-me.c | 48 ++-
drivers/misc/mei/hw-me.c | 80 ---
drivers/misc/mei/hw-me.h | 15 +++-
3 files changed, 128 insertions(+), 15 deletions(-)
diff --git a/drivers/misc/mei/gsc-me.c b/drivers/misc/mei/gsc-me.c
index c8145e9b62b6..2caba3a9ac35 100644
--- a/drivers/misc/mei/gsc-me.c
+++ b/drivers/misc/mei/gsc-me.c
@@ -13,6 +13,7 @@
#include
#include
#include
+#include
#include "mei_dev.h"
#include "hw-me.h"
@@ -66,13 +67,28 @@ static int mei_gsc_probe(struct auxiliary_device *aux_dev,
dev_set_drvdata(device, dev);
- ret = devm_request_threaded_irq(device, hw->irq,
- mei_me_irq_quick_handler,
- mei_me_irq_thread_handler,
- IRQF_ONESHOT, KBUILD_MODNAME, dev);
- if (ret) {
- dev_err(device, "irq register failed %d\n", ret);
- goto err;
+ /* use polling */
+ if (mei_me_hw_use_polling(hw)) {
+ mei_disable_interrupts(dev);
+ mei_clear_interrupts(dev);
+ init_waitqueue_head(>wait_active);
+ hw->is_active = true; /* start in active mode for
initialization */
+ hw->polling_thread = kthread_run(mei_me_polling_thread, dev,
+"kmegscirqd/%s",
dev_name(device));
+ if (IS_ERR(hw->polling_thread)) {
+ ret = PTR_ERR(hw->polling_thread);
+ dev_err(device, "unable to create kernel thread: %d\n",
ret);
+ goto err;
+ }
+ } else {
+ ret = devm_request_threaded_irq(device, hw->irq,
+ mei_me_irq_quick_handler,
+ mei_me_irq_thread_handler,
+ IRQF_ONESHOT, KBUILD_MODNAME,
dev);
+ if (ret) {
+ dev_err(device, "irq register failed %d\n", ret);
+ goto err;
+ }
}
pm_runtime_get_noresume(device);
@@ -98,7 +114,8 @@ static int mei_gsc_probe(struct auxiliary_device *aux_dev,
register_err:
mei_stop(dev);
- devm_free_irq(device, hw->irq, dev);
+ if (!mei_me_hw_use_polling(hw))
+ devm_free_irq(device, hw->irq, dev);
err:
dev_err(device, "probe failed: %d\n", ret);
@@ -119,12 +136,17 @@ static void mei_gsc_remove(struct auxiliary_device
*aux_dev)
mei_stop(dev);
+ hw = to_me_hw(dev);
+ if (mei_me_hw_use_polling(hw))
+ kthread_stop(hw->polling_thread);
+
mei_deregister(dev);
pm_runtime_disable(_dev->dev);
mei_disable_interrupts(dev);
- devm_free_irq(_dev->dev, hw->irq, dev);
+ if (!mei_me_hw_use_polling(hw))
+ devm_free_irq(_dev->dev, hw->irq, dev);
}
static int __maybe_unused mei_gsc_pm_suspend(struct device *device)
@@ -185,6 +207,9 @@ static int __maybe_unused
mei_gsc_pm_runtime_suspend(struct device *device)
if (mei_write_is_idle(dev)) {
hw = to_me_hw(dev);
hw->pg_state = MEI_PG_ON;
+
+ if (mei_me_hw_use_polling(hw))
+ hw->is_active = false;
ret = 0;
} else {
ret = -EAGAIN;
@@ -209,6 +234,11 @@ static int __maybe_unused mei_gsc_pm_runtime_resume(struct
device *device)
hw = to_me_hw(dev);
hw->pg_state = MEI_PG_OFF;
+ if (mei_me_hw_use_polling(hw)) {
+ hw->is_active = true;
+ wake_up(>wait_active);
+ }
+
mutex_unlock(>device_lock);
irq_ret = mei_me_irq_thread_handler(1, dev);
diff --git a/drivers/misc/mei/hw-me.c b/drivers/misc/mei/hw-me.c
index 3a95fe7d4e33..23ad53efbcb7 100644
--- a/drivers/misc/mei/hw-me.c
+++ b/drivers/misc/mei/hw-me.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
/*
- * Copyright (c) 2003-2020, Intel Corporation. All rights reserved.
+ * Copyright (c) 2003-2022, Intel Corporation. All rights reserved.
* Intel Management Engine Interface (Intel MEI) Linux driver
*/
@@ -10,6 +10,7 @@
#include
#include
#include
+#include
#include "mei_dev.h"
#include "hbm.h"
@@ -327,9 +328,12 @@ static void mei_me_intr_clear(struct mei_device *dev)
[Intel-gfx] [PATCH v8 06/16] mei: gsc: use polling instead of interrupts
A work-around for a HW issue in XEHPSDV that manifests itself when SW reads
a gsc register when gsc is sending an interrupt. The work-around is
to disable interrupts and to use polling instead.
Cc: James Ausmus
Signed-off-by: Vitaly Lubart
Signed-off-by: Tomas Winkler
Signed-off-by: Alexander Usyskin
---
drivers/misc/mei/gsc-me.c | 48 ++-
drivers/misc/mei/hw-me.c | 80 ---
drivers/misc/mei/hw-me.h | 15 +++-
3 files changed, 128 insertions(+), 15 deletions(-)
diff --git a/drivers/misc/mei/gsc-me.c b/drivers/misc/mei/gsc-me.c
index c8145e9b62b6..2caba3a9ac35 100644
--- a/drivers/misc/mei/gsc-me.c
+++ b/drivers/misc/mei/gsc-me.c
@@ -13,6 +13,7 @@
#include
#include
#include
+#include
#include "mei_dev.h"
#include "hw-me.h"
@@ -66,13 +67,28 @@ static int mei_gsc_probe(struct auxiliary_device *aux_dev,
dev_set_drvdata(device, dev);
- ret = devm_request_threaded_irq(device, hw->irq,
- mei_me_irq_quick_handler,
- mei_me_irq_thread_handler,
- IRQF_ONESHOT, KBUILD_MODNAME, dev);
- if (ret) {
- dev_err(device, "irq register failed %d\n", ret);
- goto err;
+ /* use polling */
+ if (mei_me_hw_use_polling(hw)) {
+ mei_disable_interrupts(dev);
+ mei_clear_interrupts(dev);
+ init_waitqueue_head(>wait_active);
+ hw->is_active = true; /* start in active mode for
initialization */
+ hw->polling_thread = kthread_run(mei_me_polling_thread, dev,
+"kmegscirqd/%s",
dev_name(device));
+ if (IS_ERR(hw->polling_thread)) {
+ ret = PTR_ERR(hw->polling_thread);
+ dev_err(device, "unable to create kernel thread: %d\n",
ret);
+ goto err;
+ }
+ } else {
+ ret = devm_request_threaded_irq(device, hw->irq,
+ mei_me_irq_quick_handler,
+ mei_me_irq_thread_handler,
+ IRQF_ONESHOT, KBUILD_MODNAME,
dev);
+ if (ret) {
+ dev_err(device, "irq register failed %d\n", ret);
+ goto err;
+ }
}
pm_runtime_get_noresume(device);
@@ -98,7 +114,8 @@ static int mei_gsc_probe(struct auxiliary_device *aux_dev,
register_err:
mei_stop(dev);
- devm_free_irq(device, hw->irq, dev);
+ if (!mei_me_hw_use_polling(hw))
+ devm_free_irq(device, hw->irq, dev);
err:
dev_err(device, "probe failed: %d\n", ret);
@@ -119,12 +136,17 @@ static void mei_gsc_remove(struct auxiliary_device
*aux_dev)
mei_stop(dev);
+ hw = to_me_hw(dev);
+ if (mei_me_hw_use_polling(hw))
+ kthread_stop(hw->polling_thread);
+
mei_deregister(dev);
pm_runtime_disable(_dev->dev);
mei_disable_interrupts(dev);
- devm_free_irq(_dev->dev, hw->irq, dev);
+ if (!mei_me_hw_use_polling(hw))
+ devm_free_irq(_dev->dev, hw->irq, dev);
}
static int __maybe_unused mei_gsc_pm_suspend(struct device *device)
@@ -185,6 +207,9 @@ static int __maybe_unused
mei_gsc_pm_runtime_suspend(struct device *device)
if (mei_write_is_idle(dev)) {
hw = to_me_hw(dev);
hw->pg_state = MEI_PG_ON;
+
+ if (mei_me_hw_use_polling(hw))
+ hw->is_active = false;
ret = 0;
} else {
ret = -EAGAIN;
@@ -209,6 +234,11 @@ static int __maybe_unused mei_gsc_pm_runtime_resume(struct
device *device)
hw = to_me_hw(dev);
hw->pg_state = MEI_PG_OFF;
+ if (mei_me_hw_use_polling(hw)) {
+ hw->is_active = true;
+ wake_up(>wait_active);
+ }
+
mutex_unlock(>device_lock);
irq_ret = mei_me_irq_thread_handler(1, dev);
diff --git a/drivers/misc/mei/hw-me.c b/drivers/misc/mei/hw-me.c
index 3a95fe7d4e33..23ad53efbcb7 100644
--- a/drivers/misc/mei/hw-me.c
+++ b/drivers/misc/mei/hw-me.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
/*
- * Copyright (c) 2003-2020, Intel Corporation. All rights reserved.
+ * Copyright (c) 2003-2022, Intel Corporation. All rights reserved.
* Intel Management Engine Interface (Intel MEI) Linux driver
*/
@@ -10,6 +10,7 @@
#include
#include
#include
+#include
#include "mei_dev.h"
#include "hbm.h"
@@ -327,9 +328,12 @@ static void mei_me_intr_clear(struct mei_device *dev)
*/
static void mei_me_intr_enable(struct mei_device *dev)
{
- u32 hcsr = mei_hcsr_read(dev);
+ u32 hcsr;
+
+ if (mei_me_hw_use_polling(to_me_hw(dev)))
+ return;
- hcsr |=
