linux-stable.git/drivers/tty/serial/sh-sci.c, branch linux-5.0.y

serial: sh-sci: Fix HSCIF RX sampling point calculation

2019-04-27T07:37:40+00:00

commit ace965696da2611af759f0284e26342b7b6cec89 upstream.

There are several issues with the formula used for calculating the
deviation from the intended rate:
  1. While min_err and last_stop are signed, srr and baud are unsigned.
     Hence the signed values are promoted to unsigned, which will lead
     to a bogus value of deviation if min_err is negative,
  2. Srr is the register field value, which is one less than the actual
     sampling rate factor,
  3. The divisions do not use rounding.

Fix this by casting unsigned variables to int, adding one to srr, and
using a single DIV_ROUND_CLOSEST().

Fixes: 63ba1e00f178a448 ("serial: sh-sci: Support for HSCIF RX sampling point adjustment")
Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Mukesh Ojha 
Cc: stable 
Reviewed-by: Ulrich Hecht 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Fix HSCIF RX sampling point adjustment

2019-04-27T07:37:40+00:00

commit 6b87784b53592a90d21576be8eff688b56d93cce upstream.

The calculation of the sampling point has min() and max() exchanged.
Fix this by using the clamp() helper instead.

Fixes: 63ba1e00f178a448 ("serial: sh-sci: Support for HSCIF RX sampling point adjustment")
Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Ulrich Hecht 
Reviewed-by: Wolfram Sang 
Acked-by: Dirk Behme 
Cc: stable 
Reviewed-by: Simon Horman 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Fix setting SCSCR_TIE while transferring data

2019-04-03T04:27:33+00:00

commit 93bcefd4c6bad4c69dbc4edcd3fbf774b24d930d upstream.

We disable transmission interrupt (clear SCSCR_TIE) after all data has been transmitted
(if uart_circ_empty(xmit)). While transmitting, if the data is still in the tty buffer,
re-enable the SCSCR_TIE bit, which was done at sci_start_tx().
This is unnecessary processing, wasting CPU operation if the data transmission length is large.
And further, transmit end, FIFO empty bits disabling have also been performed in the step above.

Signed-off-by: Hoan Nguyen An 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Do not free irqs that have already been freed

2019-01-30T08:35:46+00:00

Since IRQs might be muxed on some parts, we need to pay attention when we
are freeing them.
Otherwise we get the ugly WARNING "Trying to free already-free IRQ 20".

Fixes: 628c534ae735 ("serial: sh-sci: Improve support for separate TEI and DRI interrupts")
Cc: stable 
Signed-off-by: Chris Brandt 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Resume PIO in sci_rx_interrupt() on DMA failure

2018-12-17T14:04:11+00:00

On (H)SCIF, sci_submit_rx() is called in the receive interrupt handler.
Hence if DMA submission fails, the interrupt handler should resume
handling reception using PIO, else no more data is received.

Make sci_submit_rx() return an error indicator, so the receive interrupt
handler can act appropriately.

Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Simon Horman 
Acked-by: Wolfram Sang 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Fix crash in rx_timer_fn() on PIO fallback

2018-12-17T14:04:11+00:00

When falling back to PIO, active_rx must be set to a different value
than cookie_rx[i], else sci_dma_rx_find_active() will incorrectly find a
match, leading to a NULL pointer dereference in rx_timer_fn() later.

Use zero instead, which is the same value as after driver
initialization.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Fix locking in sci_submit_rx()

2018-12-17T14:04:11+00:00

Some callers of sci_submit_rx() hold the port spinlock, others don't.
During fallback to PIO, the driver needs to obtain the port spinlock.
If the lock was already held, spinlock recursion is detected, causing a
deadlock: BUG: spinlock recursion on CPU#0.

Fix this by adding a flag parameter to sci_submit_rx() for the caller to
indicate the port spinlock is already held, so spinlock recursion can be
avoided.

Move the spin_lock_irqsave() up, so all DMA disable steps are protected,
which is safe as the recently introduced dmaengine_terminate_async() can
be called in atomic context.

Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Simon Horman 
Signed-off-by: Greg Kroah-Hartman

Merge 4.20-rc2 into tty-next

2018-11-12T02:48:25+00:00

We want the tty/serial fixes in here as well.

Signed-off-by: Greg Kroah-Hartman

Merge tag 'tty-4.20-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2018-11-10T19:32:14+00:00

Pull tty/serial fixes from Greg KH:
 "Here are some small tty fixes for 4.20-rc2

  One of these missed the original 4.19-final release, I missed that I
  hadn't done a pull request for it as it was in linux-next and my
  branch for a long time, that's my fault.

  The others are small, fixing some reported issues and finally fixing
  the termios mess for alpha so that glibc has a chance to implement
  some missing functionality that has been pending for many years now.

  All of these have been in linux-next with no reported issues"

* tag 'tty-4.20-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: sh-sci: Fix could not remove dev_attr_rx_fifo_timeout
  arch/alpha, termios: implement BOTHER, IBSHIFT and termios2
  termios, tty/tty_baudrate.c: fix buffer overrun
  vt: fix broken display when running aptitude
  serial: sh-sci: Fix receive on SCIFA/SCIFB variants with DMA

serial: sh-sci: Fix could not remove dev_attr_rx_fifo_timeout

2018-11-09T17:34:50+00:00

This patch fixes an issue that the sci_remove() could not remove
dev_attr_rx_fifo_timeout because uart_remove_one_port() set
the port->port.type to PORT_UNKNOWN.

Reported-by: Hiromitsu Yamasaki 
Fixes: 5d23188a473d ("serial: sh-sci: make RX FIFO parameters tunable via sysfs")
Cc:  # v4.11+
Signed-off-by: Yoshihiro Shimoda 
Reviewed-by: Ulrich Hecht 
Signed-off-by: Greg Kroah-Hartman