| Message ID | 1536142147-21323-1-git-send-email-leo.yan@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | coresight: tmc: Refactor loops in etb dump | expand |
On Wed, 5 Sep 2018 at 04:09, Leo Yan <leo.yan@linaro.org> wrote: > > In ETB dump function tmc_etb_dump_hw() it has nested loops. The second > level loop is to iterate index in the range [0 .. drvdata->memwidth); > but the index isn't really used in the code, thus the second level > loop is useless. > > This patch is to remove the second level loop; the refactor also reduces > indentation and we can use 'break' to replace 'goto' tag. > > Cc: Mathieu Poirier <mathieu.poirier@linaro.org> > Signed-off-by: Leo Yan <leo.yan@linaro.org> > --- > drivers/hwtracing/coresight/coresight-tmc-etf.c | 17 +++++++---------- > 1 file changed, 7 insertions(+), 10 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c > index 9c599c9..8b34161 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c > @@ -34,23 +34,20 @@ static void tmc_etb_dump_hw(struct tmc_drvdata *drvdata) > { > char *bufp; > u32 read_data, lost; > - int i; > > /* Check if the buffer wrapped around. */ > lost = readl_relaxed(drvdata->base + TMC_STS) & TMC_STS_FULL; > bufp = drvdata->buf; > drvdata->len = 0; > while (1) { > - for (i = 0; i < drvdata->memwidth; i++) { > - read_data = readl_relaxed(drvdata->base + TMC_RRD); > - if (read_data == 0xFFFFFFFF) > - goto done; > - memcpy(bufp, &read_data, 4); > - bufp += 4; > - drvdata->len += 4; > - } > + read_data = readl_relaxed(drvdata->base + TMC_RRD); > + if (read_data == 0xFFFFFFFF) > + break; > + memcpy(bufp, &read_data, 4); > + bufp += 4; > + drvdata->len += 4; I implemented these loops in accordance with the reference manual, which is advising to read one ETB memory word at a time. But taking a step back getting rid of the inner loop yields exactly the same result. So I'll go ahead and apply your patch. Thanks, Mathieu > } > -done: > + > if (lost) > coresight_insert_barrier_packet(drvdata->buf); > return; > -- > 2.7.4 >
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c index 9c599c9..8b34161 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c @@ -34,23 +34,20 @@ static void tmc_etb_dump_hw(struct tmc_drvdata *drvdata) { char *bufp; u32 read_data, lost; - int i; /* Check if the buffer wrapped around. */ lost = readl_relaxed(drvdata->base + TMC_STS) & TMC_STS_FULL; bufp = drvdata->buf; drvdata->len = 0; while (1) { - for (i = 0; i < drvdata->memwidth; i++) { - read_data = readl_relaxed(drvdata->base + TMC_RRD); - if (read_data == 0xFFFFFFFF) - goto done; - memcpy(bufp, &read_data, 4); - bufp += 4; - drvdata->len += 4; - } + read_data = readl_relaxed(drvdata->base + TMC_RRD); + if (read_data == 0xFFFFFFFF) + break; + memcpy(bufp, &read_data, 4); + bufp += 4; + drvdata->len += 4; } -done: + if (lost) coresight_insert_barrier_packet(drvdata->buf); return;
In ETB dump function tmc_etb_dump_hw() it has nested loops. The second level loop is to iterate index in the range [0 .. drvdata->memwidth); but the index isn't really used in the code, thus the second level loop is useless. This patch is to remove the second level loop; the refactor also reduces indentation and we can use 'break' to replace 'goto' tag. Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Leo Yan <leo.yan@linaro.org> --- drivers/hwtracing/coresight/coresight-tmc-etf.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-)