/*
* timbuart.c timberdale FPGA GPIO driver
* Copyright (c) 2009 Intel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/* Supports:
* Timberdale FPGA UART
*/
#ifndef _TIMBUART_H
#define _TIMBUART_H
#define TIMBUART_FIFO_SIZE 2048
#define TIMBUART_RXFIFO 0x08
#define TIMBUART_TXFIFO 0x0c
#define TIMBUART_IER 0x10
#define TIMBUART_IPR 0x14
#define TIMBUART_ISR 0x18
#define TIMBUART_CTRL 0x1c
#define TIMBUART_BAUDRATE 0x20
#define TIMBUART_CTRL_RTS 0x01
#define TIMBUART_CTRL_CTS 0x02
#define TIMBUART_CTRL_FLSHTX 0x40
#define TIMBUART_CTRL_FLSHRX 0x80
#define TXBF 0x01
#define TXBAE 0x02
#define CTS_DELTA 0x04
#define RXDP 0x08
#define RXBAF 0x10
#define RXBF 0x20
#define RXTT 0x40
#define RXBNAE 0x80
#define TXBE 0x100
#define RXFLAGS (RXDP | RXBAF | RXBF | RXTT | RXBNAE)
#define TXFLAGS (TXBF | TXBAE)
#define TIMBUART_MAJOR 204
#define TIMBUART_MINOR 192
#endif /* _TIMBUART_H */
le class='tabs'>
dmaengine: cppi41: Fix runtime PM timeouts with USB mass storage
Commit fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support")
added runtime PM support for cppi41, but had corner case issues. Some of
the issues were fixed with commit 098de42ad670 ("dmaengine: cppi41: Fix
unpaired pm runtime when only a USB hub is connected"). That fix however
caused a new regression where we can get error -115 messages with USB on
BeagleBone when connecting a USB mass storage device to a hub.
This is because when connecting a USB mass storage device to a hub, the
initial DMA transfers can take over 200ms to complete and cppi41
autosuspend delay times out.
To fix the issue, we want to implement refcounting for chan_busy array
that contains the active dma transfers. Increasing the autosuspend delay
won't help as that the delay could be potentially seconds, and it's best
to let the USB subsystem to deal with the timeouts on errors.
The earlier attempt for runtime PM was buggy as the pm_runtime_get/put()
calls could get unpaired easily as they did not follow the state of
the chan_busy array as described in commit 098de42ad670 ("dmaengine:
cppi41: Fix unpaired pm runtime when only a USB hub is connected".
Let's fix the issue by adding pm_runtime_get() to where a new transfer
is added to the chan_busy array, and calls to pm_runtime_put() where
chan_busy array entry is cleared. This prevents any autosuspend timeouts
from happening while dma transfers are active.
Fixes: 098de42ad670 ("dmaengine: cppi41: Fix unpaired pm runtime when
only a USB hub is connected")
Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support")
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Bin Liu <b-liu@ti.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Patrick Titiano <ptitiano@baylibre.com>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Tested-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>