From 397c7729665a3b07a7b4ce7215173df8e9112809 Mon Sep 17 00:00:00 2001
From: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Date: Tue, 17 Mar 2020 08:22:10 +0200
Subject: [PATCH] intel_th: Disallow multi mode on devices where it's broken
Git-commit: 397c7729665a3b07a7b4ce7215173df8e9112809
Patch-mainline: v5.7-rc1
References: jsc#SLE-12705
Some versions of Intel TH have an issue that prevents the multi mode of
MSU from working correctly, resulting in no trace data and potentially
stuck MSU pipeline.
Disable multi mode on such devices.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200317062215.15598-2-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/hwtracing/intel_th/intel_th.h | 2 ++
drivers/hwtracing/intel_th/msu.c | 11 +++++++++--
drivers/hwtracing/intel_th/pci.c | 8 ++++++--
3 files changed, 17 insertions(+), 4 deletions(-)
diff --git a/drivers/hwtracing/intel_th/intel_th.h b/drivers/hwtracing/intel_th/intel_th.h
index 6f4f5486fe6d..5fe694708b7a 100644
--- a/drivers/hwtracing/intel_th/intel_th.h
+++ b/drivers/hwtracing/intel_th/intel_th.h
@@ -47,11 +47,13 @@ struct intel_th_output {
/**
* struct intel_th_drvdata - describes hardware capabilities and quirks
* @tscu_enable: device needs SW to enable time stamping unit
+ * @multi_is_broken: device has multiblock mode is broken
* @has_mintctl: device has interrupt control (MINTCTL) register
* @host_mode_only: device can only operate in 'host debugger' mode
*/
struct intel_th_drvdata {
unsigned int tscu_enable : 1,
+ multi_is_broken : 1,
has_mintctl : 1,
host_mode_only : 1;
};
diff --git a/drivers/hwtracing/intel_th/msu.c b/drivers/hwtracing/intel_th/msu.c
index 8e48c7458aa3..6e118b790d83 100644
--- a/drivers/hwtracing/intel_th/msu.c
+++ b/drivers/hwtracing/intel_th/msu.c
@@ -157,7 +157,8 @@ struct msc {
/* config */
unsigned int enabled : 1,
wrap : 1,
- do_irq : 1;
+ do_irq : 1,
+ multi_is_broken : 1;
unsigned int mode;
unsigned int burst_len;
unsigned int index;
@@ -1664,7 +1665,7 @@ static int intel_th_msc_init(struct msc *msc)
{
atomic_set(&msc->user_count, -1);
- msc->mode = MSC_MODE_MULTI;
+ msc->mode = msc->multi_is_broken ? MSC_MODE_SINGLE : MSC_MODE_MULTI;
mutex_init(&msc->buf_mutex);
INIT_LIST_HEAD(&msc->win_list);
INIT_LIST_HEAD(&msc->iter_list);
@@ -1876,6 +1877,9 @@ mode_store(struct device *dev, struct device_attribute *attr, const char *buf,
return -EINVAL;
found:
+ if (i == MSC_MODE_MULTI && msc->multi_is_broken)
+ return -EOPNOTSUPP;
+
mutex_lock(&msc->buf_mutex);
ret = 0;
@@ -2082,6 +2086,9 @@ static int intel_th_msc_probe(struct intel_th_device *thdev)
if (!res)
msc->do_irq = 1;
+ if (INTEL_TH_CAP(to_intel_th(thdev), multi_is_broken))
+ msc->multi_is_broken = 1;
+
msc->index = thdev->id;
msc->thdev = thdev;
diff --git a/drivers/hwtracing/intel_th/pci.c b/drivers/hwtracing/intel_th/pci.c
index e9d90b53bbc4..ad7e51ebe49e 100644
--- a/drivers/hwtracing/intel_th/pci.c
+++ b/drivers/hwtracing/intel_th/pci.c
@@ -120,6 +120,10 @@ static void intel_th_pci_remove(struct pci_dev *pdev)
pci_free_irq_vectors(pdev);
}
+static const struct intel_th_drvdata intel_th_1x_multi_is_broken = {
+ .multi_is_broken = 1,
+};
+
static const struct intel_th_drvdata intel_th_2x = {
.tscu_enable = 1,
.has_mintctl = 1,
@@ -152,7 +156,7 @@ static const struct pci_device_id intel_th_pci_id_table[] = {
{
/* Kaby Lake PCH-H */
PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0xa2a6),
- .driver_data = (kernel_ulong_t)0,
+ .driver_data = (kernel_ulong_t)&intel_th_1x_multi_is_broken,
},
{
/* Denverton */
@@ -207,7 +211,7 @@ static const struct pci_device_id intel_th_pci_id_table[] = {
{
/* Comet Lake PCH-V */
PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0xa3a6),
- .driver_data = (kernel_ulong_t)&intel_th_2x,
+ .driver_data = (kernel_ulong_t)&intel_th_1x_multi_is_broken,
},
{
/* Ice Lake NNPI */
--
2.16.4