Once reset SPI TX or RX fifo, the underlying hardware need to take
some time to actually settle down, the two bits will automatically
clear to 0, so use a poll mechanism to check status bits to make sure
it's done correctly.
On Cubie A7A board which using A733 SoC, we encoutered a SPI nor flash
timeout issue, it turns out that the SPI fifo reset take a few time to
settle down, Add a loop to poll the status.
This was the error message shows on A7A board once this issue happened.
=> sf probe
ERROR: sun4i_spi: Timeout transferring data
Failed to initialize SPI flash at 0:0 (error -2)
Signed-off-by: Yixun Lan <dlan@gentoo.org>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Acked-by: Andre Przywara <andre.przywara@arm.com>
Yixun LanandAndre Przywara
11b5cd22ba