On Fri Sep 6, 2024 at 5:46 PM EEST, Stefan Wahren wrote: > Am 06.09.24 um 11:47 schrieb Jarkko Sakkinen: > > On Fri Sep 6, 2024 at 9:09 AM EEST, Stefan Wahren wrote: > >> According to TCG PC Client Platform TPM Profile (PTP) Specification > >> only SPI mode 0 is supported. In order to ensure the SPI controller > >> supports the necessary settings, call spi_setup() and bail out > >> as soon as possible in error case. > >> > >> This change should affect all supported TPM SPI devices, because > >> tpm_tis_spi_probe is either called direct or indirectly. > >> > >> Signed-off-by: Stefan Wahren <[email protected]> > >> --- > >> drivers/char/tpm/tpm_tis_spi_main.c | 11 +++++++++++ > >> 1 file changed, 11 insertions(+) > >> > >> diff --git a/drivers/char/tpm/tpm_tis_spi_main.c > >> b/drivers/char/tpm/tpm_tis_spi_main.c > >> index 61b42c83ced8..e62d297b040e 100644 > >> --- a/drivers/char/tpm/tpm_tis_spi_main.c > >> +++ b/drivers/char/tpm/tpm_tis_spi_main.c > >> @@ -248,6 +248,17 @@ static int tpm_tis_spi_write_bytes(struct > >> tpm_tis_data *data, u32 addr, > >> int tpm_tis_spi_init(struct spi_device *spi, struct tpm_tis_spi_phy *phy, > >> int irq, const struct tpm_tis_phy_ops *phy_ops) > >> { > >> + int ret; > >> + > >> + spi->mode &= ~SPI_MODE_X_MASK; > >> + spi->mode |= SPI_MODE_0; > >> + > >> + ret = spi_setup(spi); > >> + if (ret < 0) { > >> + dev_err(&spi->dev, "SPI setup failed: %d\n", ret); > >> + return ret; > >> + } > >> + > >> phy->iobuf = devm_kmalloc(&spi->dev, SPI_HDRSIZE + MAX_SPI_FRAMESIZE, > >> GFP_KERNEL); > >> if (!phy->iobuf) > >> return -ENOMEM; > >> -- > >> 2.34.1 > > > > Why? > SPI protocol driver usually call spi_setup to verify that the SPI > controller accept the settings (SPI mode, bit, clock rate ...). Bailing > out early is more helpful for debugging issues.
What problem has this patch solved for you? I think it makes the code only less robust and more error prone. BR, Jarkko
