spi: pic32-sqi: fail transfer when the BD ring is exhausted

pic32_sqi_one_transfer() silently stopped programming buffer descriptors
when ring_desc_get() returned NULL and still returned success. The caller
then marked the last programmed descriptor as the end of the list and
started the DMA engine, so the hardware transferred only a prefix of the
requested data while the message completed with status 0.

The ring holds PESQI_BD_COUNT (256) descriptors of at most
PESQI_BD_BUF_LEN_MAX (256) bytes each, so messages larger than 64 KiB (or
with enough SG entries) can exhaust it. Since the driver sets no
max_message_size/max_transfer_size, the SPI core does not prevent this.

Return -ENOMEM instead, and set msg->status so the failure reaches the
caller rather than being silently truncated.

Fixes: 3270ac230f66 ("spi: pic32-sqi: add SPI driver for PIC32 SQI controller.")
Signed-off-by: Hongjian Dai <daihongjian@kylinsec.com.cn>
Link: https://patch.msgid.link/F5276982A630220B+20261017075545.95854-1-daihongjian@kylinsec.com.cn
Signed-off-by: Mark Brown <broonie@kernel.org>

0 files changed, 0 insertions, 0 deletions