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Date:   Fri, 01 Feb 2019 14:16:08 +0100
Message-ID: <s5ho97v8x9j.wl-tiwai@suse.de>
From:   Takashi Iwai <tiwai@suse.de>
To:     Christoph Hellwig <hch@lst.de>
Cc:     John Crispin <john@phrozen.org>, Vinod Koul <vkoul@kernel.org>,
        Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>,
        Nicolas Ferre <nicolas.ferre@microchip.com>,
        Sudip Mukherjee <sudipm.mukherjee@gmail.com>,
        Felipe Balbi <balbi@kernel.org>, linux-mips@vger.kernel.org,
        linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org,
        netdev@vger.kernel.org, linux-usb@vger.kernel.org,
        linux-fbdev@vger.kernel.org, alsa-devel@alsa-project.org,
        iommu@lists.linux-foundation.org
Subject: Re: [alsa-devel] don't pass a NULL struct device to DMA API functions
In-Reply-To: <20190201084801.10983-1-hch@lst.de>
References: <20190201084801.10983-1-hch@lst.de>
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On Fri, 01 Feb 2019 09:47:43 +0100,
Christoph Hellwig wrote:
> 
> We still have a few drivers which pass a NULL struct device pointer
> to DMA API functions, which generally is a bad idea as the API
> implementations rely on the device not only for ops selection, but
> also the dma mask and various other attributes.
> 
> This series contains all easy conversions to pass a struct device,
> besides that there also is some arch code that needs separate handling,
> a driver that should not use the DMA API at all, and one that is
> a complete basket case to be deal with separately.

Actually there are a bunch of ISA sound drivers that still call
allocators with NULL device.

The patch below should address it, although it's only compile-tested.


thanks,

Takashi

-- 8< --
From: Takashi Iwai <tiwai@suse.de>
Subject: [PATCH] ALSA: isa: Avoid passing NULL to memory allocators

We used to pass NULL to memory allocators for ISA devices due to
historical reasons.  But we prefer rather a proper device object to be
assigned, so let's fix it by replacing snd_dma_isa_data() call with
card->dev reference, and kill snd_dma_isa_data() definition.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 Documentation/sound/kernel-api/writing-an-alsa-driver.rst | 10 +++++-----
 include/sound/memalloc.h                                  |  1 -
 sound/isa/ad1816a/ad1816a_lib.c                           |  2 +-
 sound/isa/cmi8330.c                                       |  2 +-
 sound/isa/es1688/es1688_lib.c                             |  2 +-
 sound/isa/es18xx.c                                        |  2 +-
 sound/isa/gus/gus_pcm.c                                   |  4 ++--
 sound/isa/sb/sb16_main.c                                  |  2 +-
 sound/isa/sb/sb8_main.c                                   |  2 +-
 sound/isa/sscape.c                                        |  7 ++++---
 sound/isa/wss/wss_lib.c                                   |  2 +-
 11 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/Documentation/sound/kernel-api/writing-an-alsa-driver.rst b/Documentation/sound/kernel-api/writing-an-alsa-driver.rst
index 7c2f2032d30a..6b154dbb02cc 100644
--- a/Documentation/sound/kernel-api/writing-an-alsa-driver.rst
+++ b/Documentation/sound/kernel-api/writing-an-alsa-driver.rst
@@ -3520,14 +3520,14 @@ allocator will try to get an area as large as possible within the
 given size.
 
 The second argument (type) and the third argument (device pointer) are
-dependent on the bus. In the case of the ISA bus, pass
-:c:func:`snd_dma_isa_data()` as the third argument with
+dependent on the bus. For normal devices, pass the device pointer
+(typically identical as ``card->dev``) to the third argument with
 ``SNDRV_DMA_TYPE_DEV`` type. For the continuous buffer unrelated to the
 bus can be pre-allocated with ``SNDRV_DMA_TYPE_CONTINUOUS`` type and the
 ``snd_dma_continuous_data(GFP_KERNEL)`` device pointer, where
-``GFP_KERNEL`` is the kernel allocation flag to use. For the PCI
-scatter-gather buffers, use ``SNDRV_DMA_TYPE_DEV_SG`` with
-``snd_dma_pci_data(pci)`` (see the `Non-Contiguous Buffers`_
+``GFP_KERNEL`` is the kernel allocation flag to use. For the
+scatter-gather buffers, use ``SNDRV_DMA_TYPE_DEV_SG`` with the device
+pointer (see the `Non-Contiguous Buffers`_
 section).
 
 Once the buffer is pre-allocated, you can use the allocator in the
diff --git a/include/sound/memalloc.h b/include/sound/memalloc.h
index af3fa577fa06..1ac0dd82a916 100644
--- a/include/sound/memalloc.h
+++ b/include/sound/memalloc.h
@@ -37,7 +37,6 @@ struct snd_dma_device {
 };
 
 #define snd_dma_pci_data(pci)	(&(pci)->dev)
-#define snd_dma_isa_data()	NULL
 #define snd_dma_continuous_data(x)	((struct device *)(__force unsigned long)(x))
 
 
diff --git a/sound/isa/ad1816a/ad1816a_lib.c b/sound/isa/ad1816a/ad1816a_lib.c
index 61e8c7e524db..94b381a78e9e 100644
--- a/sound/isa/ad1816a/ad1816a_lib.c
+++ b/sound/isa/ad1816a/ad1816a_lib.c
@@ -693,7 +693,7 @@ int snd_ad1816a_pcm(struct snd_ad1816a *chip, int device)
 	snd_ad1816a_init(chip);
 
 	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
-					      snd_dma_isa_data(),
+					      chip->card->dev,
 					      64*1024, chip->dma1 > 3 || chip->dma2 > 3 ? 128*1024 : 64*1024);
 
 	chip->pcm = pcm;
diff --git a/sound/isa/cmi8330.c b/sound/isa/cmi8330.c
index 7e5aa06414c4..1868b73aa49c 100644
--- a/sound/isa/cmi8330.c
+++ b/sound/isa/cmi8330.c
@@ -470,7 +470,7 @@ static int snd_cmi8330_pcm(struct snd_card *card, struct snd_cmi8330 *chip)
 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &chip->streams[SNDRV_PCM_STREAM_CAPTURE].ops);
 
 	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
-					      snd_dma_isa_data(),
+					      card->dev,
 					      64*1024, 128*1024);
 	chip->pcm = pcm;
 
diff --git a/sound/isa/es1688/es1688_lib.c b/sound/isa/es1688/es1688_lib.c
index 50cdce0e8946..da341969e650 100644
--- a/sound/isa/es1688/es1688_lib.c
+++ b/sound/isa/es1688/es1688_lib.c
@@ -746,7 +746,7 @@ int snd_es1688_pcm(struct snd_card *card, struct snd_es1688 *chip, int device)
 	chip->pcm = pcm;
 
 	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
-					      snd_dma_isa_data(),
+					      card->dev,
 					      64*1024, 64*1024);
 	return 0;
 }
diff --git a/sound/isa/es18xx.c b/sound/isa/es18xx.c
index 77aa9a27fb3b..07abc7f7840c 100644
--- a/sound/isa/es18xx.c
+++ b/sound/isa/es18xx.c
@@ -1717,7 +1717,7 @@ static int snd_es18xx_pcm(struct snd_card *card, int device)
         chip->pcm = pcm;
 
 	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
-					      snd_dma_isa_data(),
+					      card->dev,
 					      64*1024,
 					      chip->dma1 > 3 || chip->dma2 > 3 ? 128*1024 : 64*1024);
 	return 0;
diff --git a/sound/isa/gus/gus_pcm.c b/sound/isa/gus/gus_pcm.c
index 131b28997e1d..b9efc6dff45d 100644
--- a/sound/isa/gus/gus_pcm.c
+++ b/sound/isa/gus/gus_pcm.c
@@ -891,7 +891,7 @@ int snd_gf1_pcm_new(struct snd_gus_card *gus, int pcm_dev, int control_index)
 
 	for (substream = pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream; substream; substream = substream->next)
 		snd_pcm_lib_preallocate_pages(substream, SNDRV_DMA_TYPE_DEV,
-					      snd_dma_isa_data(),
+					      card->dev,
 					      64*1024, gus->gf1.dma1 > 3 ? 128*1024 : 64*1024);
 	
 	pcm->info_flags = 0;
@@ -901,7 +901,7 @@ int snd_gf1_pcm_new(struct snd_gus_card *gus, int pcm_dev, int control_index)
 		if (gus->gf1.dma2 == gus->gf1.dma1)
 			pcm->info_flags |= SNDRV_PCM_INFO_HALF_DUPLEX;
 		snd_pcm_lib_preallocate_pages(pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream,
-					      SNDRV_DMA_TYPE_DEV, snd_dma_isa_data(),
+					      SNDRV_DMA_TYPE_DEV, card->dev,
 					      64*1024, gus->gf1.dma2 > 3 ? 128*1024 : 64*1024);
 	}
 	strcpy(pcm->name, pcm->id);
diff --git a/sound/isa/sb/sb16_main.c b/sound/isa/sb/sb16_main.c
index 981d65d122b6..473ec74ae48c 100644
--- a/sound/isa/sb/sb16_main.c
+++ b/sound/isa/sb/sb16_main.c
@@ -889,7 +889,7 @@ int snd_sb16dsp_pcm(struct snd_sb *chip, int device)
 	}
 
 	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
-					      snd_dma_isa_data(),
+					      card->dev,
 					      64*1024, 128*1024);
 	return 0;
 }
diff --git a/sound/isa/sb/sb8_main.c b/sound/isa/sb/sb8_main.c
index 8288fae90085..97645a732a71 100644
--- a/sound/isa/sb/sb8_main.c
+++ b/sound/isa/sb/sb8_main.c
@@ -610,7 +610,7 @@ int snd_sb8dsp_pcm(struct snd_sb *chip, int device)
 	if (chip->dma8 > 3 || chip->dma16 >= 0)
 		max_prealloc = 128 * 1024;
 	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
-					      snd_dma_isa_data(),
+					      card->dev,
 					      64*1024, max_prealloc);
 
 	return 0;
diff --git a/sound/isa/sscape.c b/sound/isa/sscape.c
index 733adee5afbf..8181db4db019 100644
--- a/sound/isa/sscape.c
+++ b/sound/isa/sscape.c
@@ -167,12 +167,13 @@ static inline struct soundscape *get_card_soundscape(struct snd_card *c)
  * I think this means that the memory has to map to
  * contiguous pages of physical memory.
  */
-static struct snd_dma_buffer *get_dmabuf(struct snd_dma_buffer *buf,
+static struct snd_dma_buffer *get_dmabuf(struct soundscape *s,
+					 struct snd_dma_buffer *buf,
 					 unsigned long size)
 {
 	if (buf) {
 		if (snd_dma_alloc_pages_fallback(SNDRV_DMA_TYPE_DEV,
-						 snd_dma_isa_data(),
+						 s->chip->card->dev,
 						 size, buf) < 0) {
 			snd_printk(KERN_ERR "sscape: Failed to allocate "
 					    "%lu bytes for DMA\n",
@@ -443,7 +444,7 @@ static int upload_dma_data(struct soundscape *s, const unsigned char *data,
 	int ret;
 	unsigned char val;
 
-	if (!get_dmabuf(&dma, PAGE_ALIGN(32 * 1024)))
+	if (!get_dmabuf(s, &dma, PAGE_ALIGN(32 * 1024)))
 		return -ENOMEM;
 
 	spin_lock_irqsave(&s->lock, flags);
diff --git a/sound/isa/wss/wss_lib.c b/sound/isa/wss/wss_lib.c
index b11ef97bce1b..0dfb8065b403 100644
--- a/sound/isa/wss/wss_lib.c
+++ b/sound/isa/wss/wss_lib.c
@@ -1942,7 +1942,7 @@ int snd_wss_pcm(struct snd_wss *chip, int device)
 	strcpy(pcm->name, snd_wss_chip_id(chip));
 
 	snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
-					      snd_dma_isa_data(),
+					      chip->card->dev,
 					      64*1024, chip->dma1 > 3 || chip->dma2 > 3 ? 128*1024 : 64*1024);
 
 	chip->pcm = pcm;
-- 
2.16.4