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* [RFC PATCH V3 07/21] mmc: core: UHS-II support, set APP_CMD bit if necessary
@ 2020-07-10 11:09 Ben Chuang
  0 siblings, 0 replies; only message in thread
From: Ben Chuang @ 2020-07-10 11:09 UTC (permalink / raw)
  To: adrian.hunter, ulf.hansson
  Cc: linux-mmc, linux-kernel, ben.chuang, takahiro.akashi, greg.tu,
	Ben Chuang

From: AKASHI Takahiro <takahiro.akashi@linaro.org>

In UHS-II mode, MMC_APP_CMD command need not to be sent.
Instead, APP_CMD bit in a packet should be set.

Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
---
 drivers/mmc/core/sd_ops.c | 9 +++++++++
 drivers/mmc/core/uhs2.c   | 4 ++++
 2 files changed, 13 insertions(+)

diff --git a/drivers/mmc/core/sd_ops.c b/drivers/mmc/core/sd_ops.c
index f58bb50872f6..9dc296356928 100644
--- a/drivers/mmc/core/sd_ops.c
+++ b/drivers/mmc/core/sd_ops.c
@@ -26,6 +26,15 @@ int mmc_app_cmd(struct mmc_host *host, struct mmc_card *card)
 	if (WARN_ON(card && card->host != host))
 		return -EINVAL;
 
+	/* UHS2 packet has APP bit so only set APP_CMD flag here.
+	 * Will set the APP bit when assembling UHS2 packet.
+	 */
+	if (host->flags &  MMC_UHS2_SUPPORT &&
+	    host->flags & MMC_UHS2_INITIALIZED) {
+		host->flags |= MMC_UHS2_APP_CMD;
+		return 0;
+	}
+
 	cmd.opcode = MMC_APP_CMD;
 
 	if (card) {
diff --git a/drivers/mmc/core/uhs2.c b/drivers/mmc/core/uhs2.c
index 6e26de429726..2fbd7b6d9dea 100644
--- a/drivers/mmc/core/uhs2.c
+++ b/drivers/mmc/core/uhs2.c
@@ -826,6 +826,10 @@ int uhs2_prepare_sd_cmd(struct mmc_host *host, struct mmc_request *mrq)
 		header |= UHS2_PACKET_TYPE_CCMD;
 
 	arg = cmd->opcode << UHS2_SD_CMD_INDEX_POS;
+	if (host->flags & MMC_UHS2_APP_CMD) {
+		arg |= UHS2_SD_CMD_APP;
+		host->flags &= ~MMC_UHS2_APP_CMD;
+	}
 
 	uhs2_cmd = cmd->uhs2_cmd;
 	payload = uhs2_cmd->payload;
-- 
2.27.0


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2020-07-10 11:09 [RFC PATCH V3 07/21] mmc: core: UHS-II support, set APP_CMD bit if necessary Ben Chuang

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