Re: [PATCH] media: imx-jpeg: Add support for descriptor allocation from SRAM

[Marek Vasut <marek.vasut@mailbox.org>]

On 8/21/25 8:28 AM, Ming Qian(OSS) wrote:
> Hi Marek,

Hello Ming,

> On 8/21/2025 12:29 AM, Marek Vasut wrote:
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>>
>> Add support for optional allocation of bitstream descriptors from SRAM
>> instead of DRAM. In case the encoder/decoder DT node contains 'sram'
>> property which points to 'mmio-sram', the driver will attempt to use
>> the SRAM instead of DRAM for descriptor allocation, which might improve
>> performance.
>>
>> This however helps on i.MX95 with sporadic SLOTn_STATUS IMG_RD_ERR bit 11
>> being triggered during JPEG encoding. The following pipeline triggers the
>> problem when descriptors get allocated from DRAM, the pipeline often 
>> hangs
>> after a few seconds and the encoder driver indicates "timeout, cancel 
>> it" :
> 
> It's a hardware bug in i.MX95 A0, and the i.MX95 B0 has fixed this issue.

Ahh, this helps, thank you.

> Using sram instead of dram only improves timing, but doesn't completely 
> circumvent the hardware bug
Does it make sense to upstream this patch anyway ?