By working with external hardware ECC engines, we figured out that Under certain circumstances, it is needed for the SPI controller to check INT_TX_EMPTY and INT_RX_NOT_EMPTY in both receive and transmit path (not only in the receive path). The delay penalty being negligible, move this code in the common path.
Fixes: b942d80b0a39 ("spi: Add MXIC controller driver") Cc: stable@vger.kernel.org Suggested-by: Mason Yang masonccyang@mxic.com.tw Signed-off-by: Miquel Raynal miquel.raynal@bootlin.com Reviewed-by: Zhengxun Li zhengxunli@mxic.com.tw Reviewed-by: Mark Brown broonie@kernel.org --- drivers/spi/spi-mxic.c | 28 ++++++++++++---------------- 1 file changed, 12 insertions(+), 16 deletions(-)
diff --git a/drivers/spi/spi-mxic.c b/drivers/spi/spi-mxic.c index 67d05ee8d6a0..aedc9a144b82 100644 --- a/drivers/spi/spi-mxic.c +++ b/drivers/spi/spi-mxic.c @@ -304,25 +304,21 @@ static int mxic_spi_data_xfer(struct mxic_spi *mxic, const void *txbuf,
writel(data, mxic->regs + TXD(nbytes % 4));
+ ret = readl_poll_timeout(mxic->regs + INT_STS, sts, + sts & INT_TX_EMPTY, 0, USEC_PER_SEC); + if (ret) + return ret; + + ret = readl_poll_timeout(mxic->regs + INT_STS, sts, + sts & INT_RX_NOT_EMPTY, 0, + USEC_PER_SEC); + if (ret) + return ret; + + data = readl(mxic->regs + RXD); if (rxbuf) { - ret = readl_poll_timeout(mxic->regs + INT_STS, sts, - sts & INT_TX_EMPTY, 0, - USEC_PER_SEC); - if (ret) - return ret; - - ret = readl_poll_timeout(mxic->regs + INT_STS, sts, - sts & INT_RX_NOT_EMPTY, 0, - USEC_PER_SEC); - if (ret) - return ret; - - data = readl(mxic->regs + RXD); data >>= (8 * (4 - nbytes)); memcpy(rxbuf + pos, &data, nbytes); - WARN_ON(readl(mxic->regs + INT_STS) & INT_RX_NOT_EMPTY); - } else { - readl(mxic->regs + RXD); } WARN_ON(readl(mxic->regs + INT_STS) & INT_RX_NOT_EMPTY);