Unverified Commit 5a1314fa authored Nov 21, 2017 by Ricardo Ribalda Committed by Mark Brown Nov 24, 2017

spi: xilinx: Detect stall with Unknown commands



When the core is configured in C_SPI_MODE > 0, it integrates a
lookup table that automatically configures the core in dual or quad mode
based on the command (first byte on the tx fifo).

Unfortunately, that list mode_?_memoy_*.mif does not contain all the
supported commands by the flash.

Since 4.14 spi-nor automatically tries to probe the flash using SFDP
(command 0x5a), and that command is not part of the list_mode table.

Whit the right combination of C_SPI_MODE and C_SPI_MEMORY this leads
into a stall that can only be recovered with a soft rest.

This patch detects this kind of stall and returns -EIO to the caller on
those commands. spi-nor can handle this error properly:

m25p80 spi0.0: Detected stall. Check C_SPI_MODE and C_SPI_MEMORY. 0x21 0x2404
m25p80 spi0.0: SPI transfer failed: -5
spi_master spi0: failed to transfer one message from queue
m25p80 spi0.0: s25sl064p (8192 Kbytes)

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

parent abbdb5ce

drivers/spi/spi-xilinx.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -271,6 +271,7 @@ static int xilinx_spi_txrx_bufs(struct spi_device spi, struct spi_transfer t)
		while (remaining_words) {
		int n_words, tx_words, rx_words;
		u32 sr;
		int stalled;

		n_words = min(remaining_words, xspi->buffer_size);

		@@ -299,7 +300,17 @@ static int xilinx_spi_txrx_bufs(struct spi_device spi, struct spi_transfer t)

		/* Read out all the data from the Rx FIFO */
		rx_words = n_words;
		stalled = 10;
		while (rx_words) {
		if (rx_words == n_words && !(stalled--) &&
		!(sr & XSPI_SR_TX_EMPTY_MASK) &&
		(sr & XSPI_SR_RX_EMPTY_MASK)) {
		dev_err(&spi->dev,
		"Detected stall. Check C_SPI_MODE and C_SPI_MEMORY\n");
		xspi_init_hw(xspi);
		return -EIO;
		}

		if ((sr & XSPI_SR_TX_EMPTY_MASK) && (rx_words > 1)) {
		xilinx_spi_rx(xspi);
		rx_words--;

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