diff options
Diffstat (limited to 'sound/core/isadma.c')
| -rw-r--r-- | sound/core/isadma.c | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/sound/core/isadma.c b/sound/core/isadma.c index 1a378951da5..31e8544d7f2 100644 --- a/sound/core/isadma.c +++ b/sound/core/isadma.c @@ -1,6 +1,6 @@ /* * ISA DMA support functions - * Copyright (c) by Jaroslav Kysela <perex@suse.cz> + * Copyright (c) by Jaroslav Kysela <perex@perex.cz> * * * This program is free software; you can redistribute it and/or modify @@ -26,7 +26,7 @@ #undef HAVE_REALLY_SLOW_DMA_CONTROLLER -#include <sound/driver.h> +#include <linux/export.h> #include <sound/core.h> #include <asm/dma.h> @@ -56,6 +56,8 @@ void snd_dma_program(unsigned long dma, release_dma_lock(flags); } +EXPORT_SYMBOL(snd_dma_program); + /** * snd_dma_disable - stop the ISA DMA transfer * @dma: the dma number @@ -72,32 +74,44 @@ void snd_dma_disable(unsigned long dma) release_dma_lock(flags); } +EXPORT_SYMBOL(snd_dma_disable); + /** * snd_dma_pointer - return the current pointer to DMA transfer buffer in bytes * @dma: the dma number * @size: the dma transfer size * - * Returns the current pointer in DMA tranfer buffer in bytes + * Return: The current pointer in DMA transfer buffer in bytes. */ unsigned int snd_dma_pointer(unsigned long dma, unsigned int size) { unsigned long flags; - unsigned int result; + unsigned int result, result1; flags = claim_dma_lock(); clear_dma_ff(dma); if (!isa_dma_bridge_buggy) disable_dma(dma); result = get_dma_residue(dma); + /* + * HACK - read the counter again and choose higher value in order to + * avoid reading during counter lower byte roll over if the + * isa_dma_bridge_buggy is set. + */ + result1 = get_dma_residue(dma); if (!isa_dma_bridge_buggy) enable_dma(dma); release_dma_lock(flags); + if (unlikely(result < result1)) + result = result1; #ifdef CONFIG_SND_DEBUG if (result > size) - snd_printk(KERN_ERR "pointer (0x%x) for DMA #%ld is greater than transfer size (0x%x)\n", result, dma, size); + pr_err("ALSA: pointer (0x%x) for DMA #%ld is greater than transfer size (0x%x)\n", result, dma, size); #endif if (result >= size || result == 0) return 0; else return size - result; } + +EXPORT_SYMBOL(snd_dma_pointer); |