AI Camera - Larger SPI transfers to enable >1MiB input tensors to be injected #7178
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pelwell
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Dec 16, 2025
drivers/spi/spi-rp2040-gpio-bridge.c
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| #define MANIFEST_HEADER_UNITS 1 | ||
| #define MANIFEST_DATA_UNITS \ | ||
| DIV_ROUND_UP(MAX_TRANSFER_SIZE, RP2040_GBDG_BLOCK_SIZE) | ||
| DIV_ROUND_UP((1024U * ONE_KIB), RP2040_GBDG_BLOCK_SIZE) |
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Is this an instance where one constant was being used for two different things?
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Thanks for highlighting this; MAX_TRANSFER_SIZE is correct here.
Increase the maximum SPI transfer size from an arbitrary 1 MiB to ~4 MiB (the amount of data that can be referenced by a single manifest). Signed-off-by: Richard Oliver <richard.oliver@raspberrypi.com>
Remove the arbitrary 1 MiB transfer limit from imx500_spi_write() as the 1 MiB chunk limitation for firmware / network transfers is already upheld by imx500_state_transition(). This allows for larger input tensors to be injected via imx500_inject_input_tensor() (where there is no 1 MiB chunk limitation). Increase the number of poll attempts whilst waiting for the injection handshake register to be TRANS_COMP to allow more time for the checksum of larger input tensors to be calculated. Alter error messages in imx500_inject_input_tensor() so that imx500_spi_write() and imx500_injection_wait_transfer_complete() errors may be more easily differentiated. Signed-off-by: Richard Oliver <richard.oliver@raspberrypi.com>
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pelwell
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Dec 16, 2025
popcornmix
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See: raspberrypi/linux#7177 kernel: AI Camera - Larger SPI transfers to enable >1MiB input tensors to be injected See: raspberrypi/linux#7178
popcornmix
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See: raspberrypi/linux#7177 kernel: AI Camera - Larger SPI transfers to enable >1MiB input tensors to be injected See: raspberrypi/linux#7178
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