On 12/04/16 18:54, Mathieu Poirier wrote:
In their current implementation the tmc_read_prepare/unprepare()
are a lump of if/else that is difficult to read.  This patch is
alleviating that by using a switch statement.  The latter also
allows for a better control on the error path.

Signed-off-by: Mathieu Poirier <mathieu.poir...@linaro.org>
---
  drivers/hwtracing/coresight/coresight-tmc.c | 56 ++++++++++++++++++-----------
  1 file changed, 36 insertions(+), 20 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-tmc.c 
b/drivers/hwtracing/coresight/coresight-tmc.c
index 66fa7736d12f..d211aeec49f8 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.c
+++ b/drivers/hwtracing/coresight/coresight-tmc.c
@@ -431,7 +431,7 @@ static const struct coresight_ops tmc_etf_cs_ops = {

  static int tmc_read_prepare(struct tmc_drvdata *drvdata)
  {
-       int ret;
+       int ret = 0;
        unsigned long flags;
        enum tmc_mode mode;

@@ -439,25 +439,31 @@ static int tmc_read_prepare(struct tmc_drvdata *drvdata)
        if (!drvdata->enable)
                goto out;

-       if (drvdata->config_type == TMC_CONFIG_TYPE_ETB) {
+       switch (drvdata->config_type) {
+       case TMC_CONFIG_TYPE_ETB:
                tmc_etb_disable_hw(drvdata);
-       } else if (drvdata->config_type == TMC_CONFIG_TYPE_ETR) {
-               tmc_etr_disable_hw(drvdata);
-       } else {
+               break;
+       case TMC_CONFIG_TYPE_ETF:
+               /* There is no point in reading a TMC in HW FIFO mode */
                mode = readl_relaxed(drvdata->base + TMC_MODE);
-               if (mode == TMC_MODE_CIRCULAR_BUFFER) {
-                       tmc_etb_disable_hw(drvdata);
-               } else {
-                       ret = -ENODEV;
+               if (mode != TMC_MODE_CIRCULAR_BUFFER) {
+                       ret = -EINVAL;
                        goto err;
                }

Nit. If you move the TMC_CONFIG_TYPE_ETB here, you could fall through from 
TYPE_ETF: i.e,
                /* Fall through to ETB mode */
        case TMC_CONFIG_TYPE_ETB:
+
+               tmc_etb_disable_hw(drvdata);
+               break;



+       case TMC_CONFIG_TYPE_ETR:
+               tmc_etr_disable_hw(drvdata);
+               break;
+       default:
+               ret = -EINVAL;
+               goto err;
        }
+


        return ret;
@@ -472,20 +478,30 @@ static void tmc_read_unprepare(struct tmc_drvdata 
*drvdata)
        if (!drvdata->enable)
                goto out;

-       if (drvdata->config_type == TMC_CONFIG_TYPE_ETB) {
+       switch (drvdata->config_type) {
+       case TMC_CONFIG_TYPE_ETB:
                tmc_etb_enable_hw(drvdata);
-       } else if (drvdata->config_type == TMC_CONFIG_TYPE_ETR) {
-               tmc_etr_enable_hw(drvdata);
-       } else {
+               break;
+       case TMC_CONFIG_TYPE_ETF:
+               /* Make sure we don't re-enable a TMC in HW FIFO mode */
                mode = readl_relaxed(drvdata->base + TMC_MODE);
-               if (mode == TMC_MODE_CIRCULAR_BUFFER)
-                       tmc_etb_enable_hw(drvdata);
+               if (mode != TMC_MODE_CIRCULAR_BUFFER)
+                       goto err;
+
+               tmc_etb_enable_hw(drvdata);
+               break;

Same as above.

+       case TMC_CONFIG_TYPE_ETR:
+               tmc_etr_disable_hw(drvdata);
+               break;
+       default:
+               goto err;
        }
+

Otherwise,

Reviewed-by: Suzuki K Poulose <suzuki.poul...@arm.com>


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