The advertisement of the persistent grants feature (writing
'feature-persistent' to xenbus) should mean not the decision for using
the feature but only the availability of the feature. However, commit
aac8a70db24b ("xen-blkback: add a parameter for disabling of persistent
grants") made a field of blkback, which was a place for saving only the
negotiation result, to be used for yet another purpose: caching of the
'feature_persistent' parameter value. As a result, the advertisement,
which should follow only the parameter value, becomes inconsistent.
This commit fixes the misuse of the semantic by making blkback saves the
parameter value in a separate place and advertises the support based on
only the saved value.
Fixes: aac8a70db24b ("xen-blkback: add a parameter for disabling of persistent grants")
Cc: <stable(a)vger.kernel.org> # 5.10.x
Suggested-by: Juergen Gross <jgross(a)suse.com>
Signed-off-by: SeongJae Park <sj(a)kernel.org>
---
drivers/block/xen-blkback/common.h | 3 +++
drivers/block/xen-blkback/xenbus.c | 6 ++++--
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h
index bda5c815e441..a28473470e66 100644
--- a/drivers/block/xen-blkback/common.h
+++ b/drivers/block/xen-blkback/common.h
@@ -226,6 +226,9 @@ struct xen_vbd {
sector_t size;
unsigned int flush_support:1;
unsigned int discard_secure:1;
+ /* Connect-time cached feature_persistent parameter value */
+ unsigned int feature_gnt_persistent_parm:1;
+ /* Persistent grants feature negotiation result */
unsigned int feature_gnt_persistent:1;
unsigned int overflow_max_grants:1;
};
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index ee7ad2fb432d..c0227dfa4688 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -907,7 +907,7 @@ static void connect(struct backend_info *be)
xen_blkbk_barrier(xbt, be, be->blkif->vbd.flush_support);
err = xenbus_printf(xbt, dev->nodename, "feature-persistent", "%u",
- be->blkif->vbd.feature_gnt_persistent);
+ be->blkif->vbd.feature_gnt_persistent_parm);
if (err) {
xenbus_dev_fatal(dev, err, "writing %s/feature-persistent",
dev->nodename);
@@ -1085,7 +1085,9 @@ static int connect_ring(struct backend_info *be)
return -ENOSYS;
}
- blkif->vbd.feature_gnt_persistent = feature_persistent &&
+ blkif->vbd.feature_gnt_persistent_parm = feature_persistent;
+ blkif->vbd.feature_gnt_persistent =
+ blkif->vbd.feature_gnt_persistent_parm &&
xenbus_read_unsigned(dev->otherend, "feature-persistent", 0);
blkif->vbd.overflow_max_grants = 0;
--
2.25.1
From: Ville Syrjälä <ville.syrjala(a)linux.intel.com>
A lot of modern laptops use the Parade PS8461E MUX for eDP
switching. The MUX can operate in jitter cleaning mode or
redriver mode, the first one resulting in higher link
quality. The jitter cleaning mode needs to know the link
rate used and the MUX achieves this by snooping the
LINK_BW_SET, LINK_RATE_SELECT and SUPPORTED_LINK_RATES
DPCD accesses.
When the MUX is powered down (seems this can happen whenever
the display is turned off) it loses track of the snooped
link rates so when we do the LINK_RATE_SELECT write it no
longer knowns which link rate we're selecting, and thus it
falls back to the lower quality redriver mode. This results
in unstable high link rates (eg. usually 8.1Gbps link rate
no longer works correctly).
In order to avoid all that let's re-snoop SUPPORTED_LINK_RATES
from the sink at the start of every link training.
Unfortunately we don't have a way to detect the presence of
the MUX. It looks like the set of laptops equipped with this
MUX is fairly large and contains devices from multiple
manufacturers. It may also still be growing with new models.
So a quirk doesn't seem like a very easily maintainable
option, thus we shall attempt to do this unconditionally on
all machines that use LINK_RATE_SELECT. Hopefully this extra
DPCD read doesn't cause issues for any unaffected machine.
If that turns out to be the case we'll need to convert this
into a quirk in the future.
Cc: stable(a)vger.kernel.org
Cc: Jason A. Donenfeld <Jason(a)zx2c4.com>
Cc: Ankit Nautiyal <ankit.k.nautiyal(a)intel.com>
Cc: Jani Nikula <jani.nikula(a)intel.com>
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6205
Signed-off-by: Ville Syrjälä <ville.syrjala(a)linux.intel.com>
---
.../drm/i915/display/intel_dp_link_training.c | 22 +++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
index 9feaf1a589f3..d213d8ad1ea5 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c
@@ -671,6 +671,28 @@ intel_dp_prepare_link_train(struct intel_dp *intel_dp,
intel_dp_compute_rate(intel_dp, crtc_state->port_clock,
&link_bw, &rate_select);
+ /*
+ * WaEdpLinkRateDataReload
+ *
+ * Parade PS8461E MUX (used on varius TGL+ laptops) needs
+ * to snoop the link rates reported by the sink when we
+ * use LINK_RATE_SET in order to operate in jitter cleaning
+ * mode (as opposed to redriver mode). Unfortunately it
+ * loses track of the snooped link rates when powered down,
+ * so we need to make it re-snoop often. Without this high
+ * link rates are not stable.
+ */
+ if (!link_bw) {
+ struct intel_connector *connector = intel_dp->attached_connector;
+ __le16 sink_rates[DP_MAX_SUPPORTED_RATES];
+
+ drm_dbg_kms(&i915->drm, "[CONNECTOR:%d:%s] Reloading eDP link rates\n",
+ connector->base.base.id, connector->base.name);
+
+ drm_dp_dpcd_read(&intel_dp->aux, DP_SUPPORTED_LINK_RATES,
+ sink_rates, sizeof(sink_rates));
+ }
+
if (link_bw)
drm_dbg_kms(&i915->drm,
"[ENCODER:%d:%s] Using LINK_BW_SET value %02x\n",
--
2.35.1
[Public]
Hi,
A sysfs file /sys/bus/thunderbolt/devices/domainX/iommu_dma_protection is exported from the kernel and used by userspace to make judgments on whether to automatically authorize PCIe tunnels for USB4 devices.
Before kernel 5.19 this file was only populated on Intel USB4 and TBT3 controllers, but starting with 5.19 it also populates for non-Intel as well.
This is accomplished by an assertion from the IOMMU subsystem that it's safe to do so by a combination of firmware and hardware.
Here is the patch series on top of 5.15.64:
3f6634d997dba8140b3a7cba01776b9638d70dff
ed36d04e8f8d7b00db451b0fa56a54e8e02ec43e
d0be55fbeb6ac694d15af5d1aad19cdec8cd64e5
f316ba0a8814f4c91e80a435da3421baf0ddd24c
f1ca70717bcb4525e29da422f3d280acbddb36fe
bfb3ba32061da1a9217ef6d02fbcffb528e4c8df
418e0a3551bbef5b221705b0e5b8412cdc0afd39
acdb89b6c87a2d7b5c48a82756e6f5c6f599f60a
ea4692c75e1c63926e4fb0728f5775ef0d733888
86eaf4a5b4312bea8676fb79399d9e08b53d8e71
Can you please consider backporting them to 5.15.y+?
I've confirmed with this series of patches that a Lenovo Z13 will populate the sysfs file and automatically authorize docks that are plugged in.
Thanks,
By rounding down, we can set a timeout value which reports spaces less
than the timeout as a timeout rather than a space.
Fixes: 877f1a7cee3f ("media: rc: mceusb: allow the timeout to be configurable")
Cc: stable(a)vger.kernel.org
Signed-off-by: Sean Young <sean(a)mess.org>
---
drivers/media/rc/mceusb.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/media/rc/mceusb.c b/drivers/media/rc/mceusb.c
index 39d2b03e2631..c76ba24c1f55 100644
--- a/drivers/media/rc/mceusb.c
+++ b/drivers/media/rc/mceusb.c
@@ -1077,7 +1077,7 @@ static int mceusb_set_timeout(struct rc_dev *dev, unsigned int timeout)
struct mceusb_dev *ir = dev->priv;
unsigned int units;
- units = DIV_ROUND_CLOSEST(timeout, MCE_TIME_UNIT);
+ units = DIV_ROUND_UP(timeout, MCE_TIME_UNIT);
cmdbuf[2] = units >> 8;
cmdbuf[3] = units;
--
2.37.2