[TW#27381] SPI_CHECK incorrect error message

[michprev]

• IDF version (run git describe --tags to find it): v3.1.1-6-g2aa9a2118

Problem Description

esp-idf/components/driver/spi_master.c

Lines 449 to 454 in fb7ba1b

	SPI_CHECK( dev_config->flags & SPI_DEVICE_HALFDUPLEX || dummy_required == 0 ||
	dev_config->flags & SPI_DEVICE_NO_DUMMY,
	"When GPIO matrix is used in full-duplex mode at frequency > %.1fMHz, device cannot read correct data.\n\
	Please note the SPI can only work at divisors of 80MHz, and the driver always tries to find the closest frequency to your configuration.\n\
	Specify ``SPI_DEVICE_NO_DUMMY`` to ignore this checking. Then you can output data at higher speed, or read data at your own risk.",
	ESP_ERR_INVALID_ARG, freq_limit/1000./1000 );

The error message talks only about situation when using SPI via GPIO matrix but the assert fails even when using SPI via native pins (which is correct).

The error message should be changed:
When GPIO matrix is used in full-duplex ... -> When SPI is used in full-duplex ...

[ginkgm]

Hi @michprev ,
thanks for your suggestions for the error message. due to histroical reason, we thought there's no reading problem with IOMUX but actually this is triggered if the MISO delay is long even with IOMUX.

We will improve this but not backporting this to earlier version.