[PATCH v2 1/4] mmc: core: Add trace event for SD SCR response

[Raul E Rangel]

Example:
sd_scr: mmc0: version: 2, spec3: 1, width: [1-BIT | 4-BIT], cmds: [], raw: 
{0x2b58000,0x0} */

Signed-off-by: Raul E Rangel <rran...@chromium.org>
---

 drivers/mmc/core/sd.c      |  6 +++++
 include/trace/events/mmc.h | 51 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 265e1aeeb9d8..f1772972d6a3 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -21,6 +21,8 @@
 #include <linux/mmc/mmc.h>
 #include <linux/mmc/sd.h>
 
+#include <trace/events/mmc.h>
+
 #include "core.h"
 #include "card.h"
 #include "host.h"
@@ -200,6 +202,7 @@ static int mmc_decode_scr(struct mmc_card *card)
        if (scr_struct != 0) {
                pr_err("%s: unrecognised SCR structure version %d\n",
                        mmc_hostname(card->host), scr_struct);
+               trace_sd_scr(card, NULL);
                return -EINVAL;
        }
 
@@ -221,6 +224,9 @@ static int mmc_decode_scr(struct mmc_card *card)
 
        if (scr->sda_spec3)
                scr->cmds = UNSTUFF_BITS(resp, 32, 2);
+
+       trace_sd_scr(card, scr);
+
        return 0;
 }
 
diff --git a/include/trace/events/mmc.h b/include/trace/events/mmc.h
index 7b706ff21335..9761d3db16db 100644
--- a/include/trace/events/mmc.h
+++ b/include/trace/events/mmc.h
@@ -10,6 +10,57 @@
 #include <linux/mmc/host.h>
 #include <linux/tracepoint.h>
 
+#define SD_SCR_WIDTH_FLAGS             \
+       {SD_SCR_BUS_WIDTH_1, "1-BIT"},  \
+       {SD_SCR_BUS_WIDTH_4, "4-BIT"}
+
+#define SD_SCR_CMD_FLAGS               \
+       {SD_SCR_CMD20_SUPPORT, "CMD20"},\
+       {SD_SCR_CMD23_SUPPORT, "CMD23"}
+
+TRACE_EVENT(sd_scr,
+
+       TP_PROTO(struct mmc_card *card, struct sd_scr *scr),
+
+       TP_ARGS(card, scr),
+
+       TP_STRUCT__entry(
+               __array(u32,                    raw,    2)
+               __field(unsigned char,          sda_vsn)
+               __field(unsigned char,          sda_spec3)
+               __field(unsigned char,          bus_widths)
+               __field(unsigned char,          cmds)
+               __string(name,                  mmc_hostname(card->host))
+       ),
+
+       TP_fast_assign(
+               BUILD_BUG_ON(sizeof(card->raw_scr) != sizeof(__entry->raw));
+               memcpy(__entry->raw, card->raw_scr, sizeof(__entry->raw));
+               if (scr) {
+                       __entry->sda_vsn = scr->sda_vsn;
+                       __entry->sda_spec3 = scr->sda_spec3;
+                       __entry->bus_widths = scr->bus_widths;
+                       __entry->cmds = scr->cmds;
+               } else {
+                       __entry->sda_vsn = 0;
+                       __entry->sda_spec3 = 0;
+                       __entry->bus_widths = 0;
+                       __entry->cmds = 0;
+               }
+               __assign_str(name, mmc_hostname(card->host));
+       ),
+
+       TP_printk("%s: version: %d, spec3: %d, width: [%s], cmds: [%s], "
+                 "raw: %s",
+                 __get_str(name),
+                 __entry->sda_vsn,
+                 __entry->sda_spec3,
+                 __print_flags(__entry->bus_widths, " | ", SD_SCR_WIDTH_FLAGS),
+                 __print_flags(__entry->cmds, " | ", SD_SCR_CMD_FLAGS),
+                 __print_array(__entry->raw, 2, sizeof(u32))
+       )
+);
+
 TRACE_EVENT(mmc_request_start,
 
        TP_PROTO(struct mmc_host *host, struct mmc_request *mrq),
-- 
2.21.0.392.gf8f6787159e-goog