spi: spi-geni-qcom: Don't keep a local state variable

The variable "cur_mcmd" kept track of our current state (idle, xfer,
cs, cancel).  We don't really need it, so get rid of it.  Instead:
* Use separate condition variables for "chip select done", "cancel
  done", and "abort done".  This is important so that if a "done"
  comes through (perhaps some previous interrupt finally came through)
  it can't confuse the cancel/abort function.
* Use the "done" interrupt only for when a chip select or transfer is
  done and we can tell the difference by looking at whether "cur_xfer"
  is NULL.

This is mostly a no-op change.  However, it is possible it could fix
an issue where a super delayed interrupt for a cancel command could
have confused our waiting for an abort command.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20200618080459.v4.5.Ib1e6855405fc9c99916ab7c7dee84d73a8bf3d68@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c
index 5b8ca8b..0c534d1 100644 (file)
--- a/drivers/spi/spi-geni-qcom.c
+++ b/drivers/spi/spi-geni-qcom.c
@@ -63,13 +63,6 @@
 #define TIMESTAMP_AFTER                BIT(3)
 #define POST_CMD_DELAY         BIT(4)
 
-enum spi_m_cmd_opcode {
-       CMD_NONE,
-       CMD_XFER,
-       CMD_CS,
-       CMD_CANCEL,
-};
-
 struct spi_geni_master {
        struct geni_se se;
        struct device *dev;
@@ -81,10 +74,11 @@ struct spi_geni_master {
        unsigned int tx_rem_bytes;
        unsigned int rx_rem_bytes;
        const struct spi_transfer *cur_xfer;
-       struct completion xfer_done;
+       struct completion cs_done;
+       struct completion cancel_done;
+       struct completion abort_done;
        unsigned int oversampling;
        spinlock_t lock;
-       enum spi_m_cmd_opcode cur_mcmd;
        int irq;
 };
 
@@ -126,20 +120,23 @@ static void handle_fifo_timeout(struct spi_master *spi,
        struct geni_se *se = &mas->se;
 
        spin_lock_irq(&mas->lock);
-       reinit_completion(&mas->xfer_done);
-       mas->cur_mcmd = CMD_CANCEL;
-       geni_se_cancel_m_cmd(se);
+       reinit_completion(&mas->cancel_done);
        writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
+       mas->cur_xfer = NULL;
+       mas->tx_rem_bytes = mas->rx_rem_bytes = 0;
+       geni_se_cancel_m_cmd(se);
        spin_unlock_irq(&mas->lock);
-       time_left = wait_for_completion_timeout(&mas->xfer_done, HZ);
+
+       time_left = wait_for_completion_timeout(&mas->cancel_done, HZ);
        if (time_left)
                return;
 
        spin_lock_irq(&mas->lock);
-       reinit_completion(&mas->xfer_done);
+       reinit_completion(&mas->abort_done);
        geni_se_abort_m_cmd(se);
        spin_unlock_irq(&mas->lock);
-       time_left = wait_for_completion_timeout(&mas->xfer_done, HZ);
+
+       time_left = wait_for_completion_timeout(&mas->abort_done, HZ);
        if (!time_left)
                dev_err(mas->dev, "Failed to cancel/abort m_cmd\n");
 }
@@ -156,15 +153,14 @@ static void spi_geni_set_cs(struct spi_device *slv, bool set_flag)
                set_flag = !set_flag;
 
        spin_lock_irq(&mas->lock);
-       reinit_completion(&mas->xfer_done);
-       mas->cur_mcmd = CMD_CS;
+       reinit_completion(&mas->cs_done);
        if (set_flag)
                geni_se_setup_m_cmd(se, SPI_CS_ASSERT, 0);
        else
                geni_se_setup_m_cmd(se, SPI_CS_DEASSERT, 0);
        spin_unlock_irq(&mas->lock);
 
-       time_left = wait_for_completion_timeout(&mas->xfer_done, HZ);
+       time_left = wait_for_completion_timeout(&mas->cs_done, HZ);
        if (!time_left)
                handle_fifo_timeout(spi, NULL);
 
@@ -383,7 +379,6 @@ static void setup_fifo_xfer(struct spi_transfer *xfer,
                mas->rx_rem_bytes = xfer->len;
        }
        writel(spi_tx_cfg, se->base + SE_SPI_TRANS_CFG);
-       mas->cur_mcmd = CMD_XFER;
 
        /*
         * Lock around right before we start the transfer since our
@@ -520,11 +515,13 @@ static irqreturn_t geni_spi_isr(int irq, void *data)
                geni_spi_handle_tx(mas);
 
        if (m_irq & M_CMD_DONE_EN) {
-               if (mas->cur_mcmd == CMD_XFER)
+               if (mas->cur_xfer) {
                        spi_finalize_current_transfer(spi);
-               else if (mas->cur_mcmd == CMD_CS)
-                       complete(&mas->xfer_done);
-               mas->cur_mcmd = CMD_NONE;
+                       mas->cur_xfer = NULL;
+               } else {
+                       complete(&mas->cs_done);
+               }
+
                /*
                 * If this happens, then a CMD_DONE came before all the Tx
                 * buffer bytes were sent out. This is unusual, log this
@@ -546,10 +543,10 @@ static irqreturn_t geni_spi_isr(int irq, void *data)
                                mas->rx_rem_bytes, mas->cur_bits_per_word);
        }
 
-       if ((m_irq & M_CMD_CANCEL_EN) || (m_irq & M_CMD_ABORT_EN)) {
-               mas->cur_mcmd = CMD_NONE;
-               complete(&mas->xfer_done);
-       }
+       if (m_irq & M_CMD_CANCEL_EN)
+               complete(&mas->cancel_done);
+       if (m_irq & M_CMD_ABORT_EN)
+               complete(&mas->abort_done);
 
        /*
         * It's safe or a good idea to Ack all of our our interrupts at the
@@ -617,7 +614,9 @@ static int spi_geni_probe(struct platform_device *pdev)
        spi->handle_err = handle_fifo_timeout;
        spi->set_cs = spi_geni_set_cs;
 
-       init_completion(&mas->xfer_done);
+       init_completion(&mas->cs_done);
+       init_completion(&mas->cancel_done);
+       init_completion(&mas->abort_done);
        spin_lock_init(&mas->lock);
        pm_runtime_enable(dev);