This is a note to let you know that I've just added the patch titled
phy: lantiq: rcu-usb2: wait after clock enable
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
>From 36acd5e24e3000691fb8d1ee31cf959cb1582d35 Mon Sep 17 00:00:00 2001
From: Mathias Kresin <dev(a)kresin.me>
Date: Thu, 7 Jan 2021 23:49:01 +0100
Subject: phy: lantiq: rcu-usb2: wait after clock enable
Commit 65dc2e725286 ("usb: dwc2: Update Core Reset programming flow.")
revealed that the phy isn't ready immediately after enabling it's
clocks. The dwc2_check_core_version() fails and the dwc2 usb driver
errors out.
Add a short delay to let the phy get up and running. There isn't any
documentation how much time is required, the value was chosen based on
tests.
Signed-off-by: Mathias Kresin <dev(a)kresin.me>
Acked-by: Hauke Mehrtens <hauke(a)hauke-m.de>
Acked-by: Martin Blumenstingl <martin.blumenstingl(a)googlemail.com>
Cc: <stable(a)vger.kernel.org> # v5.7+
Link: https://lore.kernel.org/r/20210107224901.2102479-1-dev@kresin.me
Signed-off-by: Vinod Koul <vkoul(a)kernel.org>
---
drivers/phy/lantiq/phy-lantiq-rcu-usb2.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/phy/lantiq/phy-lantiq-rcu-usb2.c b/drivers/phy/lantiq/phy-lantiq-rcu-usb2.c
index a7d126192cf1..29d246ea24b4 100644
--- a/drivers/phy/lantiq/phy-lantiq-rcu-usb2.c
+++ b/drivers/phy/lantiq/phy-lantiq-rcu-usb2.c
@@ -124,8 +124,16 @@ static int ltq_rcu_usb2_phy_power_on(struct phy *phy)
reset_control_deassert(priv->phy_reset);
ret = clk_prepare_enable(priv->phy_gate_clk);
- if (ret)
+ if (ret) {
dev_err(dev, "failed to enable PHY gate\n");
+ return ret;
+ }
+
+ /*
+ * at least the xrx200 usb2 phy requires some extra time to be
+ * operational after enabling the clock
+ */
+ usleep_range(100, 200);
return ret;
}
--
2.30.1
From: Gao Xiang <hsiangkao(a)redhat.com>
Currently, although set_bit() & test_bit() pairs are used as a fast-
path for initialized configurations. However, these atomic ops are
actually relaxed forms. Instead, load-acquire & store-release form is
needed to make sure uninitialized fields won't be observed in advance
here (yet no such corresponding bitops so use full barriers instead.)
Fixes: 62dc45979f3f ("staging: erofs: fix race of initializing xattrs of a inode at the same time")
Fixes: 152a333a5895 ("staging: erofs: add compacted compression indexes support")
Cc: <stable(a)vger.kernel.org> # 5.3+
Reported-by: Huang Jianan <huangjianan(a)oppo.com>
Signed-off-by: Gao Xiang <hsiangkao(a)redhat.com>
---
fs/erofs/xattr.c | 10 +++++++++-
fs/erofs/zmap.c | 10 +++++++++-
2 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c
index 5bde77d70852..47314a26767a 100644
--- a/fs/erofs/xattr.c
+++ b/fs/erofs/xattr.c
@@ -48,8 +48,14 @@ static int init_inode_xattrs(struct inode *inode)
int ret = 0;
/* the most case is that xattrs of this inode are initialized. */
- if (test_bit(EROFS_I_EA_INITED_BIT, &vi->flags))
+ if (test_bit(EROFS_I_EA_INITED_BIT, &vi->flags)) {
+ /*
+ * paired with smp_mb() at the end of the function to ensure
+ * fields will only be observed after the bit is set.
+ */
+ smp_mb();
return 0;
+ }
if (wait_on_bit_lock(&vi->flags, EROFS_I_BL_XATTR_BIT, TASK_KILLABLE))
return -ERESTARTSYS;
@@ -137,6 +143,8 @@ static int init_inode_xattrs(struct inode *inode)
}
xattr_iter_end(&it, atomic_map);
+ /* paired with smp_mb() at the beginning of the function. */
+ smp_mb();
set_bit(EROFS_I_EA_INITED_BIT, &vi->flags);
out_unlock:
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index ae325541884e..14d2de35110c 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -36,8 +36,14 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
void *kaddr;
struct z_erofs_map_header *h;
- if (test_bit(EROFS_I_Z_INITED_BIT, &vi->flags))
+ if (test_bit(EROFS_I_Z_INITED_BIT, &vi->flags)) {
+ /*
+ * paired with smp_mb() at the end of the function to ensure
+ * fields will only be observed after the bit is set.
+ */
+ smp_mb();
return 0;
+ }
if (wait_on_bit_lock(&vi->flags, EROFS_I_BL_Z_BIT, TASK_KILLABLE))
return -ERESTARTSYS;
@@ -83,6 +89,8 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
vi->z_physical_clusterbits[1] = vi->z_logical_clusterbits +
((h->h_clusterbits >> 5) & 7);
+ /* paired with smp_mb() at the beginning of the function */
+ smp_mb();
set_bit(EROFS_I_Z_INITED_BIT, &vi->flags);
unmap_done:
kunmap_atomic(kaddr);
--
2.24.0