<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git, branch v4.14.190</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v4.14.190</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v4.14.190'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2020-07-29T05:42:58+00:00</updated>
<entry>
<title>Linux 4.14.190</title>
<updated>2020-07-29T05:42:58+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2020-07-29T05:42:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=e5a54aa2d312e75fe4bc66c7b84400b02266e946'/>
<id>urn:sha1:e5a54aa2d312e75fe4bc66c7b84400b02266e946</id>
<content type='text'>
Tested-by: Shuah Khan &lt;skhan@linuxfoundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>ath9k: Fix regression with Atheros 9271</title>
<updated>2020-07-29T05:42:58+00:00</updated>
<author>
<name>Mark O'Donovan</name>
<email>shiftee@posteo.net</email>
</author>
<published>2020-07-11T04:33:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=d560e7b5e990052c320f594911cc0705dd085048'/>
<id>urn:sha1:d560e7b5e990052c320f594911cc0705dd085048</id>
<content type='text'>
commit 92f53e2fda8bb9a559ad61d57bfb397ce67ed0ab upstream.

This fix allows ath9k_htc modules to connect to WLAN once again.

Fixes: 2bbcaaee1fcb ("ath9k: Fix general protection fault in ath9k_hif_usb_rx_cb")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=208251
Signed-off-by: Mark O'Donovan &lt;shiftee@posteo.net&gt;
Reported-by: Roman Mamedov &lt;rm@romanrm.net&gt;
Tested-by: Viktor Jägersküpper &lt;viktor_jaegerskuepper@freenet.de&gt;
Signed-off-by: Kalle Valo &lt;kvalo@codeaurora.org&gt;
Link: https://lore.kernel.org/r/20200711043324.8079-1-shiftee@posteo.net
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>ath9k: Fix general protection fault in ath9k_hif_usb_rx_cb</title>
<updated>2020-07-29T05:42:58+00:00</updated>
<author>
<name>Qiujun Huang</name>
<email>hqjagain@gmail.com</email>
</author>
<published>2020-04-04T04:18:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=ecb8ccca5631af1b71b245d7278ca6b219165842'/>
<id>urn:sha1:ecb8ccca5631af1b71b245d7278ca6b219165842</id>
<content type='text'>
commit 2bbcaaee1fcbd83272e29f31e2bb7e70d8c49e05 upstream.

In ath9k_hif_usb_rx_cb interface number is assumed to be 0.
usb_ifnum_to_if(urb-&gt;dev, 0)
But it isn't always true.

The case reported by syzbot:
https://lore.kernel.org/linux-usb/000000000000666c9c05a1c05d12@google.com
usb 2-1: new high-speed USB device number 2 using dummy_hcd
usb 2-1: config 1 has an invalid interface number: 2 but max is 0
usb 2-1: config 1 has no interface number 0
usb 2-1: New USB device found, idVendor=0cf3, idProduct=9271, bcdDevice=
1.08
usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
general protection fault, probably for non-canonical address
0xdffffc0000000015: 0000 [#1] SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000000a8-0x00000000000000af]
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc5-syzkaller #0

Call Trace
__usb_hcd_giveback_urb+0x29a/0x550 drivers/usb/core/hcd.c:1650
usb_hcd_giveback_urb+0x368/0x420 drivers/usb/core/hcd.c:1716
dummy_timer+0x1258/0x32ae drivers/usb/gadget/udc/dummy_hcd.c:1966
call_timer_fn+0x195/0x6f0 kernel/time/timer.c:1404
expire_timers kernel/time/timer.c:1449 [inline]
__run_timers kernel/time/timer.c:1773 [inline]
__run_timers kernel/time/timer.c:1740 [inline]
run_timer_softirq+0x5f9/0x1500 kernel/time/timer.c:1786
__do_softirq+0x21e/0x950 kernel/softirq.c:292
invoke_softirq kernel/softirq.c:373 [inline]
irq_exit+0x178/0x1a0 kernel/softirq.c:413
exiting_irq arch/x86/include/asm/apic.h:546 [inline]
smp_apic_timer_interrupt+0x141/0x540 arch/x86/kernel/apic/apic.c:1146
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829

Reported-and-tested-by: syzbot+40d5d2e8a4680952f042@syzkaller.appspotmail.com
Signed-off-by: Qiujun Huang &lt;hqjagain@gmail.com&gt;
Signed-off-by: Kalle Valo &lt;kvalo@codeaurora.org&gt;
Link: https://lore.kernel.org/r/20200404041838.10426-6-hqjagain@gmail.com
Cc: Viktor Jägersküpper &lt;viktor_jaegerskuepper@freenet.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>parisc: Add atomic64_set_release() define to avoid CPU soft lockups</title>
<updated>2020-07-29T05:42:58+00:00</updated>
<author>
<name>John David Anglin</name>
<email>dave.anglin@bell.net</email>
</author>
<published>2020-07-21T11:36:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=438d96367d039a98030f32224232062f0b8d7f7d'/>
<id>urn:sha1:438d96367d039a98030f32224232062f0b8d7f7d</id>
<content type='text'>
commit be6577af0cef934ccb036445314072e8cb9217b9 upstream.

Stalls are quite frequent with recent kernels. I enabled
CONFIG_SOFTLOCKUP_DETECTOR and I caught the following stall:

watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [cc1:22803]
CPU: 0 PID: 22803 Comm: cc1 Not tainted 5.6.17+ #3
Hardware name: 9000/800/rp3440
 IAOQ[0]: d_alloc_parallel+0x384/0x688
 IAOQ[1]: d_alloc_parallel+0x388/0x688
 RP(r2): d_alloc_parallel+0x134/0x688
Backtrace:
 [&lt;000000004036974c&gt;] __lookup_slow+0xa4/0x200
 [&lt;0000000040369fc8&gt;] walk_component+0x288/0x458
 [&lt;000000004036a9a0&gt;] path_lookupat+0x88/0x198
 [&lt;000000004036e748&gt;] filename_lookup+0xa0/0x168
 [&lt;000000004036e95c&gt;] user_path_at_empty+0x64/0x80
 [&lt;000000004035d93c&gt;] vfs_statx+0x104/0x158
 [&lt;000000004035dfcc&gt;] __do_sys_lstat64+0x44/0x80
 [&lt;000000004035e5a0&gt;] sys_lstat64+0x20/0x38
 [&lt;0000000040180054&gt;] syscall_exit+0x0/0x14

The code was stuck in this loop in d_alloc_parallel:

    4037d414:   0e 00 10 dc     ldd 0(r16),ret0
    4037d418:   c7 fc 5f ed     bb,&lt; ret0,1f,4037d414 &lt;d_alloc_parallel+0x384&gt;
    4037d41c:   08 00 02 40     nop

This is the inner loop of bit_spin_lock which is called by hlist_bl_unlock in
d_alloc_parallel:

static inline void bit_spin_lock(int bitnum, unsigned long *addr)
{
        /*
         * Assuming the lock is uncontended, this never enters
         * the body of the outer loop. If it is contended, then
         * within the inner loop a non-atomic test is used to
         * busywait with less bus contention for a good time to
         * attempt to acquire the lock bit.
         */
        preempt_disable();
#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
        while (unlikely(test_and_set_bit_lock(bitnum, addr))) {
                preempt_enable();
                do {
                        cpu_relax();
                } while (test_bit(bitnum, addr));
                preempt_disable();
        }
#endif
        __acquire(bitlock);
}

After consideration, I realized that we must be losing bit unlocks.
Then, I noticed that we missed defining atomic64_set_release().
Adding this define fixes the stalls in bit operations.

Signed-off-by: Dave Anglin &lt;dave.anglin@bell.net&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>io-mapping: indicate mapping failure</title>
<updated>2020-07-29T05:42:58+00:00</updated>
<author>
<name>Michael J. Ruhl</name>
<email>michael.j.ruhl@intel.com</email>
</author>
<published>2020-07-24T04:15:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=01f2b73e0da2d2396d254b69bf23a3620269d575'/>
<id>urn:sha1:01f2b73e0da2d2396d254b69bf23a3620269d575</id>
<content type='text'>
commit e0b3e0b1a04367fc15c07f44e78361545b55357c upstream.

The !ATOMIC_IOMAP version of io_maping_init_wc will always return
success, even when the ioremap fails.

Since the ATOMIC_IOMAP version returns NULL when the init fails, and
callers check for a NULL return on error this is unexpected.

During a device probe, where the ioremap failed, a crash can look like
this:

    BUG: unable to handle page fault for address: 0000000000210000
     #PF: supervisor write access in kernel mode
     #PF: error_code(0x0002) - not-present page
     Oops: 0002 [#1] PREEMPT SMP
     CPU: 0 PID: 177 Comm:
     RIP: 0010:fill_page_dma [i915]
       gen8_ppgtt_create [i915]
       i915_ppgtt_create [i915]
       intel_gt_init [i915]
       i915_gem_init [i915]
       i915_driver_probe [i915]
       pci_device_probe
       really_probe
       driver_probe_device

The remap failure occurred much earlier in the probe.  If it had been
propagated, the driver would have exited with an error.

Return NULL on ioremap failure.

[akpm@linux-foundation.org: detect ioremap_wc() errors earlier]

Fixes: cafaf14a5d8f ("io-mapping: Always create a struct to hold metadata about the io-mapping")
Signed-off-by: Michael J. Ruhl &lt;michael.j.ruhl@intel.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Reviewed-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Mike Rapoport &lt;rppt@linux.ibm.com&gt;
Cc: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Cc: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: Daniel Vetter &lt;daniel@ffwll.ch&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Link: http://lkml.kernel.org/r/20200721171936.81563-1-michael.j.ruhl@intel.com
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>mm/memcg: fix refcount error while moving and swapping</title>
<updated>2020-07-29T05:42:57+00:00</updated>
<author>
<name>Hugh Dickins</name>
<email>hughd@google.com</email>
</author>
<published>2020-07-24T04:15:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=a0c487460ce9e00c88658b293461764f29092fd5'/>
<id>urn:sha1:a0c487460ce9e00c88658b293461764f29092fd5</id>
<content type='text'>
commit 8d22a9351035ef2ff12ef163a1091b8b8cf1e49c upstream.

It was hard to keep a test running, moving tasks between memcgs with
move_charge_at_immigrate, while swapping: mem_cgroup_id_get_many()'s
refcount is discovered to be 0 (supposedly impossible), so it is then
forced to REFCOUNT_SATURATED, and after thousands of warnings in quick
succession, the test is at last put out of misery by being OOM killed.

This is because of the way moved_swap accounting was saved up until the
task move gets completed in __mem_cgroup_clear_mc(), deferred from when
mem_cgroup_move_swap_account() actually exchanged old and new ids.
Concurrent activity can free up swap quicker than the task is scanned,
bringing id refcount down 0 (which should only be possible when
offlining).

Just skip that optimization: do that part of the accounting immediately.

Fixes: 615d66c37c75 ("mm: memcontrol: fix memcg id ref counter on swap charge move")
Signed-off-by: Hugh Dickins &lt;hughd@google.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Reviewed-by: Alex Shi &lt;alex.shi@linux.alibaba.com&gt;
Cc: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Alex Shi &lt;alex.shi@linux.alibaba.com&gt;
Cc: Shakeel Butt &lt;shakeelb@google.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2007071431050.4726@eggly.anvils
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>Makefile: Fix GCC_TOOLCHAIN_DIR prefix for Clang cross compilation</title>
<updated>2020-07-29T05:42:57+00:00</updated>
<author>
<name>Fangrui Song</name>
<email>maskray@google.com</email>
</author>
<published>2020-07-21T17:31:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=71749b1181eca12af96654a781cabcd058c37c8f'/>
<id>urn:sha1:71749b1181eca12af96654a781cabcd058c37c8f</id>
<content type='text'>
commit ca9b31f6bb9c6aa9b4e5f0792f39a97bbffb8c51 upstream.

When CROSS_COMPILE is set (e.g. aarch64-linux-gnu-), if
$(CROSS_COMPILE)elfedit is found at /usr/bin/aarch64-linux-gnu-elfedit,
GCC_TOOLCHAIN_DIR will be set to /usr/bin/.  --prefix= will be set to
/usr/bin/ and Clang as of 11 will search for both
$(prefix)aarch64-linux-gnu-$needle and $(prefix)$needle.

GCC searchs for $(prefix)aarch64-linux-gnu/$version/$needle,
$(prefix)aarch64-linux-gnu/$needle and $(prefix)$needle. In practice,
$(prefix)aarch64-linux-gnu/$needle rarely contains executables.

To better model how GCC's -B/--prefix takes in effect in practice, newer
Clang (since
https://github.com/llvm/llvm-project/commit/3452a0d8c17f7166f479706b293caf6ac76ffd90)
only searches for $(prefix)$needle. Currently it will find /usr/bin/as
instead of /usr/bin/aarch64-linux-gnu-as.

Set --prefix= to $(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE))
(/usr/bin/aarch64-linux-gnu-) so that newer Clang can find the
appropriate cross compiling GNU as (when -no-integrated-as is in
effect).

Cc: stable@vger.kernel.org
Reported-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Signed-off-by: Fangrui Song &lt;maskray@google.com&gt;
Reviewed-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Tested-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Tested-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Link: https://github.com/ClangBuiltLinux/linux/issues/1099
Reviewed-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>vt: Reject zero-sized screen buffer size.</title>
<updated>2020-07-29T05:42:57+00:00</updated>
<author>
<name>Tetsuo Handa</name>
<email>penguin-kernel@I-love.SAKURA.ne.jp</email>
</author>
<published>2020-07-12T11:10:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=7cecdf9655ef285b52583f861c2de5193fbbd461'/>
<id>urn:sha1:7cecdf9655ef285b52583f861c2de5193fbbd461</id>
<content type='text'>
commit ce684552a266cb1c7cc2f7e623f38567adec6653 upstream.

syzbot is reporting general protection fault in do_con_write() [1] caused
by vc-&gt;vc_screenbuf == ZERO_SIZE_PTR caused by vc-&gt;vc_screenbuf_size == 0
caused by vc-&gt;vc_cols == vc-&gt;vc_rows == vc-&gt;vc_size_row == 0 caused by
fb_set_var() from ioctl(FBIOPUT_VSCREENINFO) on /dev/fb0 , for
gotoxy(vc, 0, 0) from reset_terminal() from vc_init() from vc_allocate()
 from con_install() from tty_init_dev() from tty_open() on such console
causes vc-&gt;vc_pos == 0x10000000e due to
((unsigned long) ZERO_SIZE_PTR) + -1U * 0 + (-1U &lt;&lt; 1).

I don't think that a console with 0 column or 0 row makes sense. And it
seems that vc_do_resize() does not intend to allow resizing a console to
0 column or 0 row due to

  new_cols = (cols ? cols : vc-&gt;vc_cols);
  new_rows = (lines ? lines : vc-&gt;vc_rows);

exception.

Theoretically, cols and rows can be any range as long as
0 &lt; cols * rows * 2 &lt;= KMALLOC_MAX_SIZE is satisfied (e.g.
cols == 1048576 &amp;&amp; rows == 2 is possible) because of

  vc-&gt;vc_size_row = vc-&gt;vc_cols &lt;&lt; 1;
  vc-&gt;vc_screenbuf_size = vc-&gt;vc_rows * vc-&gt;vc_size_row;

in visual_init() and kzalloc(vc-&gt;vc_screenbuf_size) in vc_allocate().

Since we can detect cols == 0 or rows == 0 via screenbuf_size = 0 in
visual_init(), we can reject kzalloc(0). Then, vc_allocate() will return
an error, and con_write() will not be called on a console with 0 column
or 0 row.

We need to make sure that integer overflow in visual_init() won't happen.
Since vc_do_resize() restricts cols &lt;= 32767 and rows &lt;= 32767, applying
1 &lt;= cols &lt;= 32767 and 1 &lt;= rows &lt;= 32767 restrictions to vc_allocate()
will be practically fine.

This patch does not touch con_init(), for returning -EINVAL there
does not help when we are not returning -ENOMEM.

[1] https://syzkaller.appspot.com/bug?extid=017265e8553724e514e8

Reported-and-tested-by: syzbot &lt;syzbot+017265e8553724e514e8@syzkaller.appspotmail.com&gt;
Signed-off-by: Tetsuo Handa &lt;penguin-kernel@I-love.SAKURA.ne.jp&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Link: https://lore.kernel.org/r/20200712111013.11881-1-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>fbdev: Detect integer underflow at "struct fbcon_ops"-&gt;clear_margins.</title>
<updated>2020-07-29T05:42:57+00:00</updated>
<author>
<name>Tetsuo Handa</name>
<email>penguin-kernel@I-love.SAKURA.ne.jp</email>
</author>
<published>2020-07-15T01:51:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=c388072f90cc2d5884cf42e0c6d605d65d323b41'/>
<id>urn:sha1:c388072f90cc2d5884cf42e0c6d605d65d323b41</id>
<content type='text'>
commit 033724d6864245a11f8e04c066002e6ad22b3fd0 upstream.

syzbot is reporting general protection fault in bitfill_aligned() [1]
caused by integer underflow in bit_clear_margins(). The cause of this
problem is when and how do_vc_resize() updates vc-&gt;vc_{cols,rows}.

If vc_do_resize() fails (e.g. kzalloc() fails) when var.xres or var.yres
is going to shrink, vc-&gt;vc_{cols,rows} will not be updated. This allows
bit_clear_margins() to see info-&gt;var.xres &lt; (vc-&gt;vc_cols * cw) or
info-&gt;var.yres &lt; (vc-&gt;vc_rows * ch). Unexpectedly large rw or bh will
try to overrun the __iomem region and causes general protection fault.

Also, vc_resize(vc, 0, 0) does not set vc-&gt;vc_{cols,rows} = 0 due to

  new_cols = (cols ? cols : vc-&gt;vc_cols);
  new_rows = (lines ? lines : vc-&gt;vc_rows);

exception. Since cols and lines are calculated as

  cols = FBCON_SWAP(ops-&gt;rotate, info-&gt;var.xres, info-&gt;var.yres);
  rows = FBCON_SWAP(ops-&gt;rotate, info-&gt;var.yres, info-&gt;var.xres);
  cols /= vc-&gt;vc_font.width;
  rows /= vc-&gt;vc_font.height;
  vc_resize(vc, cols, rows);

in fbcon_modechanged(), var.xres &lt; vc-&gt;vc_font.width makes cols = 0
and var.yres &lt; vc-&gt;vc_font.height makes rows = 0. This means that

  const int fd = open("/dev/fb0", O_ACCMODE);
  struct fb_var_screeninfo var = { };
  ioctl(fd, FBIOGET_VSCREENINFO, &amp;var);
  var.xres = var.yres = 1;
  ioctl(fd, FBIOPUT_VSCREENINFO, &amp;var);

easily reproduces integer underflow bug explained above.

Of course, callers of vc_resize() are not handling vc_do_resize() failure
is bad. But we can't avoid vc_resize(vc, 0, 0) which returns 0. Therefore,
as a band-aid workaround, this patch checks integer underflow in
"struct fbcon_ops"-&gt;clear_margins call, assuming that
vc-&gt;vc_cols * vc-&gt;vc_font.width and vc-&gt;vc_rows * vc-&gt;vc_font.heigh do not
cause integer overflow.

[1] https://syzkaller.appspot.com/bug?id=a565882df74fa76f10d3a6fec4be31098dbb37c6

Reported-and-tested-by: syzbot &lt;syzbot+e5fd3e65515b48c02a30@syzkaller.appspotmail.com&gt;
Signed-off-by: Tetsuo Handa &lt;penguin-kernel@I-love.SAKURA.ne.jp&gt;
Acked-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Link: https://lore.kernel.org/r/20200715015102.3814-1-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>serial: 8250_mtk: Fix high-speed baud rates clamping</title>
<updated>2020-07-29T05:42:57+00:00</updated>
<author>
<name>Serge Semin</name>
<email>Sergey.Semin@baikalelectronics.ru</email>
</author>
<published>2020-07-14T12:41:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=ead742adb0195bca0be3d2e63c453be14814aa8c'/>
<id>urn:sha1:ead742adb0195bca0be3d2e63c453be14814aa8c</id>
<content type='text'>
commit 551e553f0d4ab623e2a6f424ab5834f9c7b5229c upstream.

Commit 7b668c064ec3 ("serial: 8250: Fix max baud limit in generic 8250
port") fixed limits of a baud rate setting for a generic 8250 port.
In other words since that commit the baud rate has been permitted to be
within [uartclk / 16 / UART_DIV_MAX; uartclk / 16], which is absolutely
normal for a standard 8250 UART port. But there are custom 8250 ports,
which provide extended baud rate limits. In particular the Mediatek 8250
port can work with baud rates up to "uartclk" speed.

Normally that and any other peculiarity is supposed to be handled in a
custom set_termios() callback implemented in the vendor-specific
8250-port glue-driver. Currently that is how it's done for the most of
the vendor-specific 8250 ports, but for some reason for Mediatek a
solution has been spread out to both the glue-driver and to the generic
8250-port code. Due to that a bug has been introduced, which permitted the
extended baud rate limit for all even for standard 8250-ports. The bug
has been fixed by the commit 7b668c064ec3 ("serial: 8250: Fix max baud
limit in generic 8250 port") by narrowing the baud rates limit back down to
the normal bounds. Unfortunately by doing so we also broke the
Mediatek-specific extended bauds feature.

A fix of the problem described above is twofold. First since we can't get
back the extended baud rate limits feature to the generic set_termios()
function and that method supports only a standard baud rates range, the
requested baud rate must be locally stored before calling it and then
restored back to the new termios structure after the generic set_termios()
finished its magic business. By doing so we still use the
serial8250_do_set_termios() method to set the LCR/MCR/FCR/etc. registers,
while the extended baud rate setting procedure will be performed later in
the custom Mediatek-specific set_termios() callback. Second since a true
baud rate is now fully calculated in the custom set_termios() method we
need to locally update the port timeout by calling the
uart_update_timeout() function. After the fixes described above are
implemented in the 8250_mtk.c driver, the Mediatek 8250-port should
get back to normally working with extended baud rates.

Link: https://lore.kernel.org/linux-serial/20200701211337.3027448-1-danielwinkler@google.com

Fixes: 7b668c064ec3 ("serial: 8250: Fix max baud limit in generic 8250 port")
Reported-by: Daniel Winkler &lt;danielwinkler@google.com&gt;
Signed-off-by: Serge Semin &lt;Sergey.Semin@baikalelectronics.ru&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Tested-by: Claire Chang &lt;tientzu@chromium.org&gt;
Link: https://lore.kernel.org/r/20200714124113.20918-1-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
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