linux.git/drivers/tty/serial/sh-sci.c, branch v4.19-rc2

serial: sh-sci: Improve support for separate TEI and DRI interrupts

2018-08-02T08:07:09+00:00

Some SCIF versions mux error and break interrupts together and then provide
a separate interrupt ID for just TEI/DRI.

Allow all 6 types of interrupts to be specified via platform data (or DT)
and for any signals that are muxed together (have the same interrupt
number) simply register one handler.

Signed-off-by: Chris Brandt 
Reviewed-by: Geert Uytterhoeven 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Remove SCIx_RZ_SCIFA_REGTYPE

2018-08-02T08:07:09+00:00

There is no more need for SCIx_RZ_SCIFA_REGTYPE now that
SCIx_SH4_SCIF_REGTYPE can provide the same register/address definitions.

Also, R7S9210 no longer needs a special compatible since the standard
"renesas,scif" will work just fine.

Signed-off-by: Chris Brandt 
Reviewed-by: Geert Uytterhoeven 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Allow for compressed SCIF address

2018-08-02T08:07:09+00:00

Some devices with SCIx_SH4_SCIF_REGTYPE have no space between registers.
Use the register area size to determine the spacing between register.

Signed-off-by: Chris Brandt 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Drop superfluous assignment in sci_request_dma()

2018-07-21T06:40:51+00:00

No later code uses the assigned value, so it can be dropped.

Reported-by: Simon Horman 
Fixes: 2c4ee23530ffc022 ("serial: sh-sci: Postpone DMA release when falling back to PIO")
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Fix use-after-free on subsequent port startup

2018-07-21T06:39:25+00:00

sci_request_irq() checks port->irqstr[j] for a NULL pointer, to decide
if a fallback interrupt name string should be allocated or not.

While this string is freed during port shutdown, the pointer is not
zeroed.  Hence on a subsequent startup of the port, it will still be
pointing to the freed memory, leading to e.g.

    WARNING: CPU: 0 PID: 404 at fs/proc/generic.c:388 __proc_create+0xbc/0x260
    name len 0

or to a crash (the latter is more likely with CONFIG_DEBUG_SLAB=y, due
to the poisoning of freed memory).

Instead of zeroeing the pointer at multiple places, preinitialize
port->irqstr[j] to zero to fix this.

Fixes: 8b0bbd956228ae87 ("serial: sh-sci: Add support for R7S9210")
Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Ulrich Hecht 
Reviewed-by: Simon Horman 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Add support for R7S9210

2018-07-16T09:56:22+00:00

Add support for a "RZ_SCIFA" which is different than a traditional
SCIFA. It looks like a normal SCIF with FIFO data, but with a
compressed address space. Also, the break out of interrupts
are different then traditinal SCIF: ERI/BRI, RXI, TXI, TEI, DRI.
The R7S9210 (RZ/A2) contains this type of SCIF.

Signed-off-by: Chris Brandt 
Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Stop using deprecated dmaengine_terminate_all()

2018-07-06T14:41:15+00:00

As of commit b36f09c3c441a6e5 ("dmaengine: Add transfer termination
synchronization support"), dmaengine_terminate_all() is deprecated.

Replace calls to dmaengine_terminate_all() in DMA release code by calls
to dmaengine_terminate_sync(), as the latter waits until all running
completion callbacks have finished.

Replace calls to dmaengine_terminate_all() in DMA failure paths by calls
to dmaengine_terminate_async(), as these are usually done in atomic
context.

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

serial: sh-sci: Stop TX DMA workqueue during port shutdown

2018-07-06T14:41:15+00:00

The transmit DMA workqueue is never stopped, hence the work function may
be called after the port has been shut down.

Fix this race condition by cancelling queued work, if any, before DMA
release.  Don't initialize the work if DMA initialization failed, as it
won't be used anyway.

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

serial: sh-sci: Postpone DMA release when falling back to PIO

2018-07-06T14:41:15+00:00

When the sh-sci driver detects an issue with DMA during operation, it
falls backs to PIO, and releases all DMA resources.

As releasing DMA resources immediately has no advantages, but
complicates the code, and is susceptible to races, it is better to
postpone this to port shutdown.

This allows to remove the locking from sci_rx_dma_release() and
sci_tx_dma_release(), but requires keeping a copy of the DMA channel
pointers for release during port shutdown.

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

serial: sh-sci: Stop RX FIFO timer during port shutdown

2018-07-06T14:41:15+00:00

The RX FIFO timer may be armed when the port is shut down, hence the
timer function may still be called afterwards.

Fix this race condition by deleting the timer during port shutdown.

Fixes: 039403765e5da3c6 ("serial: sh-sci: SCIFA/B RX FIFO software timeout")
Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Simon Horman 
Signed-off-by: Greg Kroah-Hartman