Make spi_ppc4xx.c tolerate 0 bits-per-word and 0 speed_hz
PATCH 1/1 Make spi_ppc4xx.c tolerate 0 bits-per-word and 0 speed_hz
If a SPI transfer is set up, but does not explicitly set bits-per-word and speed_hz, then the transaction fails, because spi_ppc4xx_setupxfer rejects it.
This patch modifies the logic to chose the struct spi_transfer parameters only if they are non-zero. Otherwise, the struct spi_device parameters are used.
Additionally, since there is no OF binding for bits-per-word, we have to tolerate the case where both t->bits_per_word and spi->bits_per_word are zero.
---
This was brought to light by a pending patch to spi_bitbang, which results in more calls to spi_ppc4xx_setupxfer.
drivers/spi/spi_ppc4xx.c | 22 +++++++++++++++------- 1 files changed, 15 insertions(+), 7 deletions(-)
drivers/spi/spi_ppc4xx.c +15 -7
@@ -151,16 +151,24 @@ static int spi_ppc4xx_setupxfer(struct spi_device *spi, struct spi_transfer *t)/* Write new configration */ out_8 (&hw->regs->mode, cs->mode); +/* Start with the generic configuration for this device. */ + bpw = spi->bits_per_word; + cs->speed_hz = spi->max_speed_hz; +/* -* Allow platform reduce the interrupt load on the CPU during SPI -* transfers. We do not target maximum performance, but rather allow -* platform to limit SPI bus frequency and interrupt rate. +* Allow the platform to reduce the interrupt load on the CPU during +* SPI transfers. We do not target maximum performance, but rather +* allow the platform to limit SPI bus frequency and interrupt rate. */ - bpw = t ? t->bits_per_word : spi->bits_per_word; - cs->speed_hz = t ?min (t->speed_hz, spi->max_speed_hz) : - spi->max_speed_hz; +if (t) { +if (t->bits_per_word) + bpw = t->bits_per_word; + +if (t->speed_hz) + cs->speed_hz =min (t->speed_hz, spi->max_speed_hz); + } -if (bpw !=8 ) { +if (bpw && bpw !=8 ) {dev_err (&spi->dev,"invalid bits-per-word (%d)\n" , bpw);return -EINVAL ; }
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1.6.0.2