0dce49efc7
A potential bug was reported in the email "[BUG] atmel_ssc_dai: a possible sleep-in-atomic bug in atmel_ssc_shutdown"[1] Indeed in the function atmel_ssc_shutdown() free_irq() was called in a critical section protected by spinlock. However this spinlock is only used in atmel_ssc_shutdown() and atmel_ssc_startup() functions. After further analysis, it occurred that the call to these function are already protected by mutex used on the calling functions. Then we can remove the spinlock which will fix this bug as a side effect. Thanks to this patch the following message disappears: "BUG: sleeping function called from invalid context at kernel/locking/mutex.c:909" [1]: https://www.spinics.net/lists/alsa-devel/msg71286.html Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com> Link: https://lore.kernel.org/r/20190918100344.23629-1-gregory.clement@bootlin.com Signed-off-by: Mark Brown <broonie@kernel.org>
112 lines
2.6 KiB
C
112 lines
2.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* atmel_ssc_dai.h - ALSA SSC interface for the Atmel SoC
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*
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* Copyright (C) 2005 SAN People
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* Copyright (C) 2008 Atmel
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*
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* Author: Sedji Gaouaou <sedji.gaouaou@atmel.com>
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* ATMEL CORP.
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*
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* Based on at91-ssc.c by
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* Frank Mandarino <fmandarino@endrelia.com>
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* Based on pxa2xx Platform drivers by
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* Liam Girdwood <lrg@slimlogic.co.uk>
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*/
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#ifndef _ATMEL_SSC_DAI_H
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#define _ATMEL_SSC_DAI_H
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#include <linux/types.h>
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#include <linux/atmel-ssc.h>
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#include "atmel-pcm.h"
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/* SSC system clock ids */
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#define ATMEL_SYSCLK_MCK 0 /* SSC uses AT91 MCK as system clock */
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/* SSC divider ids */
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#define ATMEL_SSC_CMR_DIV 0 /* MCK divider for BCLK */
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#define ATMEL_SSC_TCMR_PERIOD 1 /* BCLK divider for transmit FS */
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#define ATMEL_SSC_RCMR_PERIOD 2 /* BCLK divider for receive FS */
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/*
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* SSC direction masks
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*/
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#define SSC_DIR_MASK_UNUSED 0
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#define SSC_DIR_MASK_PLAYBACK 1
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#define SSC_DIR_MASK_CAPTURE 2
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/*
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* SSC register values that Atmel left out of <linux/atmel-ssc.h>. These
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* are expected to be used with SSC_BF
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*/
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/* START bit field values */
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#define SSC_START_CONTINUOUS 0
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#define SSC_START_TX_RX 1
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#define SSC_START_LOW_RF 2
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#define SSC_START_HIGH_RF 3
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#define SSC_START_FALLING_RF 4
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#define SSC_START_RISING_RF 5
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#define SSC_START_LEVEL_RF 6
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#define SSC_START_EDGE_RF 7
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#define SSS_START_COMPARE_0 8
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/* CKI bit field values */
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#define SSC_CKI_FALLING 0
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#define SSC_CKI_RISING 1
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/* CKO bit field values */
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#define SSC_CKO_NONE 0
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#define SSC_CKO_CONTINUOUS 1
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#define SSC_CKO_TRANSFER 2
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/* CKS bit field values */
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#define SSC_CKS_DIV 0
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#define SSC_CKS_CLOCK 1
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#define SSC_CKS_PIN 2
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/* FSEDGE bit field values */
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#define SSC_FSEDGE_POSITIVE 0
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#define SSC_FSEDGE_NEGATIVE 1
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/* FSOS bit field values */
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#define SSC_FSOS_NONE 0
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#define SSC_FSOS_NEGATIVE 1
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#define SSC_FSOS_POSITIVE 2
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#define SSC_FSOS_LOW 3
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#define SSC_FSOS_HIGH 4
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#define SSC_FSOS_TOGGLE 5
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#define START_DELAY 1
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struct atmel_ssc_state {
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u32 ssc_cmr;
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u32 ssc_rcmr;
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u32 ssc_rfmr;
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u32 ssc_tcmr;
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u32 ssc_tfmr;
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u32 ssc_sr;
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u32 ssc_imr;
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};
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struct atmel_ssc_info {
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char *name;
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struct ssc_device *ssc;
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unsigned short dir_mask; /* 0=unused, 1=playback, 2=capture */
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unsigned short initialized; /* true if SSC has been initialized */
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unsigned short daifmt;
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unsigned short cmr_div;
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unsigned short tcmr_period;
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unsigned short rcmr_period;
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unsigned int forced_divider;
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struct atmel_pcm_dma_params *dma_params[2];
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struct atmel_ssc_state ssc_state;
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unsigned long mck_rate;
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};
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int atmel_ssc_set_audio(int ssc_id);
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void atmel_ssc_put_audio(int ssc_id);
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#endif /* _AT91_SSC_DAI_H */
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