From 397c7729665a3b07a7b4ce7215173df8e9112809 Mon Sep 17 00:00:00 2001 From: Alexander Shishkin Date: Tue, 17 Mar 2020 08:22:10 +0200 Subject: intel_th: Disallow multi mode on devices where it's broken 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 Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20200317062215.15598-2-alexander.shishkin@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/intel_th/msu.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'drivers/hwtracing/intel_th/msu.c') 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; -- cgit v1.2.3