RE: RE: RE: [PATCH v2 4/5] media: chips-media: wave5: drop "sram-size" DT prop

[Nas Chung <nas.chung@chipsnmedia.com>]

Hi, Sebastian.

>-----Original Message-----
>From: Ivan Bornyakov <brnkv.i1@gmail.com>
>Sent: Thursday, March 28, 2024 8:36 PM
>To: Nas Chung <nas.chung@chipsnmedia.com>
>Cc: linux-media@vger.kernel.org; linux-kernel@vger.kernel.org;
>jackson.lee <jackson.lee@chipsnmedia.com>; Mauro Carvalho Chehab
><mchehab@kernel.org>; Philipp Zabel <p.zabel@pengutronix.de>
>Subject: Re: RE: RE: [PATCH v2 4/5] media: chips-media: wave5: drop
>"sram-size" DT prop
>
>On Thu, Mar 28, 2024 at 10:16:53AM +0000, Nas Chung wrote:
>> Hi, Ivan.
>>
>> >-----Original Message-----
>> >From: Ivan Bornyakov <brnkv.i1@gmail.com>
>> >Sent: Wednesday, March 27, 2024 9:27 PM
>> >To: Nas Chung <nas.chung@chipsnmedia.com>
>> >Cc: linux-media@vger.kernel.org; linux-kernel@vger.kernel.org;
>> >jackson.lee <jackson.lee@chipsnmedia.com>; Mauro Carvalho Chehab
>> ><mchehab@kernel.org>; Philipp Zabel <p.zabel@pengutronix.de>
>> >Subject: Re: RE: [PATCH v2 4/5] media: chips-media: wave5: drop "sram-
>> >size" DT prop
>> >
>> >On Wed, Mar 27, 2024 at 10:27:19AM +0000, Nas Chung wrote:
>> >> Hi, Ivan.
>> >>
>> >> >-----Original Message-----
>> >> >From: Ivan Bornyakov <brnkv.i1@gmail.com>
>> >> >Sent: Monday, March 25, 2024 3:41 PM
>> >> >To: Nas Chung <nas.chung@chipsnmedia.com>; jackson.lee
>> >> ><jackson.lee@chipsnmedia.com>; Mauro Carvalho Chehab
>> ><mchehab@kernel.org>;
>> >> >Philipp Zabel <p.zabel@pengutronix.de>
>> >> >Cc: Ivan Bornyakov <brnkv.i1@gmail.com>; linux-
>media@vger.kernel.org;
>> >> >linux-kernel@vger.kernel.org
>> >> >Subject: [PATCH v2 4/5] media: chips-media: wave5: drop "sram-size"
>DT
>> >> >prop
>> >> >
>> >> >Use all available SRAM memory up to WAVE5_MAX_SRAM_SIZE. Remove
>> >> >excessive "sram-size" device-tree property as genalloc is already
>able
>> >> >to determine available memory.
>> >> >
>> >> >Signed-off-by: Ivan Bornyakov <brnkv.i1@gmail.com>
>> >> >---
>> >> > .../platform/chips-media/wave5/wave5-vdi.c    | 21 ++++++++++------
>---
>> >> > .../platform/chips-media/wave5/wave5-vpu.c    |  7 -------
>> >> > .../platform/chips-media/wave5/wave5-vpuapi.h |  1 -
>> >> > .../chips-media/wave5/wave5-vpuconfig.h       |  2 ++
>> >> > 4 files changed, 13 insertions(+), 18 deletions(-)
>> >> >
>> >> >diff --git a/drivers/media/platform/chips-media/wave5/wave5-vdi.c
>> >> >b/drivers/media/platform/chips-media/wave5/wave5-vdi.c
>> >> >index 3809f70bc0b4..a63fffed55e9 100644
>> >> >--- a/drivers/media/platform/chips-media/wave5/wave5-vdi.c
>> >> >+++ b/drivers/media/platform/chips-media/wave5/wave5-vdi.c
>> >> >@@ -174,16 +174,19 @@ int wave5_vdi_allocate_array(struct
>vpu_device
>> >> >*vpu_dev, struct vpu_buf *array,
>> >> > void wave5_vdi_allocate_sram(struct vpu_device *vpu_dev)
>> >> > {
>> >> > 	struct vpu_buf *vb = &vpu_dev->sram_buf;
>> >> >+	dma_addr_t daddr;
>> >> >+	void *vaddr;
>> >> >+	size_t size;
>> >> >
>> >> >-	if (!vpu_dev->sram_pool || !vpu_dev->sram_size)
>> >> >+	if (!vpu_dev->sram_pool || vb->vaddr)
>> >> > 		return;
>> >> >
>> >> >-	if (!vb->vaddr) {
>> >> >-		vb->size = vpu_dev->sram_size;
>> >> >-		vb->vaddr = gen_pool_dma_alloc(vpu_dev->sram_pool, vb-
>>size,
>> >> >-					       &vb->daddr);
>> >> >-		if (!vb->vaddr)
>> >> >-			vb->size = 0;
>> >> >+	size = min_t(size_t, WAVE5_MAX_SRAM_SIZE,
>gen_pool_avail(vpu_dev-
>> >> >>sram_pool));
>> >> >+	vaddr = gen_pool_dma_alloc(vpu_dev->sram_pool, size, &daddr);
>> >> >+	if (vaddr) {
>> >> >+		vb->vaddr = vaddr;
>> >> >+		vb->daddr = daddr;
>> >> >+		vb->size = size;
>> >> > 	}
>> >> >
>> >> > 	dev_dbg(vpu_dev->dev, "%s: sram daddr: %pad, size: %zu,
>vaddr:
>> >> >0x%p\n",
>> >> >@@ -197,9 +200,7 @@ void wave5_vdi_free_sram(struct vpu_device
>> >*vpu_dev)
>> >> > 	if (!vb->size || !vb->vaddr)
>> >> > 		return;
>> >> >
>> >> >-	if (vb->vaddr)
>> >> >-		gen_pool_free(vpu_dev->sram_pool, (unsigned long)vb-
>>vaddr,
>> >> >-			      vb->size);
>> >> >+	gen_pool_free(vpu_dev->sram_pool, (unsigned long)vb->vaddr,
>vb-
>> >> >>size);
>> >> >
>> >> > 	memset(vb, 0, sizeof(*vb));
>> >> > }
>> >> >diff --git a/drivers/media/platform/chips-media/wave5/wave5-vpu.c
>> >> >b/drivers/media/platform/chips-media/wave5/wave5-vpu.c
>> >> >index 1e631da58e15..2a972cddf4a6 100644
>> >> >--- a/drivers/media/platform/chips-media/wave5/wave5-vpu.c
>> >> >+++ b/drivers/media/platform/chips-media/wave5/wave5-vpu.c
>> >> >@@ -177,13 +177,6 @@ static int wave5_vpu_probe(struct
>platform_device
>> >> >*pdev)
>> >> > 		goto err_reset_assert;
>> >> > 	}
>> >> >
>> >> >-	ret = of_property_read_u32(pdev->dev.of_node, "sram-size",
>> >> >-				   &dev->sram_size);
>> >> >-	if (ret) {
>> >> >-		dev_warn(&pdev->dev, "sram-size not found\n");
>> >> >-		dev->sram_size = 0;
>> >> >-	}
>> >> >-
>> >> > 	dev->sram_pool = of_gen_pool_get(pdev->dev.of_node, "sram",
>0);
>> >> > 	if (!dev->sram_pool)
>> >> > 		dev_warn(&pdev->dev, "sram node not found\n");
>> >> >diff --git a/drivers/media/platform/chips-media/wave5/wave5-
>vpuapi.h
>> >> >b/drivers/media/platform/chips-media/wave5/wave5-vpuapi.h
>> >> >index da530fd98964..975d96b22191 100644
>> >> >--- a/drivers/media/platform/chips-media/wave5/wave5-vpuapi.h
>> >> >+++ b/drivers/media/platform/chips-media/wave5/wave5-vpuapi.h
>> >> >@@ -750,7 +750,6 @@ struct vpu_device {
>> >> > 	struct vpu_attr attr;
>> >> > 	struct vpu_buf common_mem;
>> >> > 	u32 last_performance_cycles;
>> >> >-	u32 sram_size;
>> >> > 	struct gen_pool *sram_pool;
>> >> > 	struct vpu_buf sram_buf;
>> >> > 	void __iomem *vdb_register;
>> >> >diff --git a/drivers/media/platform/chips-media/wave5/wave5-
>> >vpuconfig.h
>> >> >b/drivers/media/platform/chips-media/wave5/wave5-vpuconfig.h
>> >> >index d9751eedb0f9..9d99afb78c89 100644
>> >> >--- a/drivers/media/platform/chips-media/wave5/wave5-vpuconfig.h
>> >> >+++ b/drivers/media/platform/chips-media/wave5/wave5-vpuconfig.h
>> >> >@@ -28,6 +28,8 @@
>> >> > #define WAVE521ENC_WORKBUF_SIZE         (128 * 1024)      //HEVC 128K,
>> >AVC
>> >> >40K
>> >> > #define WAVE521DEC_WORKBUF_SIZE         (1784 * 1024)
>> >> >
>> >> >+#define WAVE5_MAX_SRAM_SIZE		(64 * 1024)
>> >>
>> >> WAVE521 can support 8K stream decoding/encoding.
>> >> So, I suggest the MAX_SRAME_SIZE to 128 * 1024 (128KB).
>> >>
>> >> And, Current driver always enable sec_axi_info option if sram buffer
>is
>> >allocated.
>> >> But, we have to enable/disable the sec_axi_info option after
>checking
>> >the allocated sram size is enough to decode/encode current bitstream
>> >resolution.
>> >
>> >Do we really? As an experiment I tried to provide to Wave515 1KB of
>SRAM
>> >memory and decoded 4k sample file was fine...
>> >
>>
>> You can think It seems like driver works fine.
>> But, This is not the behavior we expect.
>> There is a possibility that unexpected problems may occur.
>>
>
>Ok, then we either
>
> 1) don't try to allocate any availible SRAM memory up to
>    match_data->sram_size, but allocate exact match_data->sram_size
>
>or
>
> 2) allocate any available SRAM memory up to match_data->sram_size, but
>    check for allocated size before writing to registers W5_USE_SEC_AXI
>    and W5_CMD_ENC_PIC_USE_SEC_AXI
>
>With second variant I won't be able to add said check for Wave521, as I
>don't know its memory requirements.
>
>Also would this check be SoC specific or would it be common for any SoC
>with same Wave5xx IP?
>
>> >> Wave5 can enable/disable the sec_axi_info option for each instance.
>> >>
>> >> How about handle sram-size through match_data ?
>> >> I can find some drivers which use match_data to configure the sram
>size.

I proposed using match_data to allocate different sram size for each device.
Do you think this is a reasonable approach ?

Thanks.
Nas.

>> >>
>> >> We can use current "ti,k3-j721s2-wave521c" device as a 4K supported
>> >device.
>> >> - .sram_size = (64 * 1024);
>> >> Driver just allocate the sram-size for max supported resolution of
>each
>> >device, and we don't need to check the sram-size is enough or not.
>> >>
>> >> Thanks.
>> >> Nas.
>> >>
>> >> >+
>> >> > #define MAX_NUM_INSTANCE                32
>> >> >
>> >> > #define W5_MIN_ENC_PIC_WIDTH            256
>> >> >--
>> >> >2.44.0
>> >>