4.14-stable review patch. If anyone has any objections, please let me know.
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From: Ricardo Ribalda Delgado ricardo.ribalda@gmail.com
commit 5a1314fa697fc65cefaba64cd4699bfc3e6882a6 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/spi/spi-xilinx.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
--- a/drivers/spi/spi-xilinx.c +++ b/drivers/spi/spi-xilinx.c @@ -271,6 +271,7 @@ static int xilinx_spi_txrx_bufs(struct s 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 s
/* 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--;