mail archive of the barebox mailing list
 help / color / mirror / Atom feed
From: Robert Jarzmik <robert.jarzmik@free.fr>
To: barebox@lists.infradead.org
Subject: [PATCH] drivers/mci: fix read/write stalling
Date: Mon, 27 Feb 2012 23:45:28 +0100	[thread overview]
Message-ID: <1330382728-10708-1-git-send-email-robert.jarzmik@free.fr> (raw)

If a read or write operation encounters an error, the card
might stay in "recv" or "data" state, and never get back to
"tran" state.

In these cases, the host is required to send a CMD12 (end
transmission) to switch the FSM of the card back to "tran"
state, as described in MMC Specification, chapter "Data
Transfer Mode".

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
---
 drivers/mci/mci-core.c |   31 ++++++++++---------------------
 1 files changed, 10 insertions(+), 21 deletions(-)

diff --git a/drivers/mci/mci-core.c b/drivers/mci/mci-core.c
index 0bf4449..6432391 100644
--- a/drivers/mci/mci-core.c
+++ b/drivers/mci/mci-core.c
@@ -101,7 +101,7 @@ static int mci_set_blocklen(struct mci *mci, unsigned len)
 static void *sector_buf;
 
 /**
- * Write one block of data to the card
+ * Write one or several blocks of data to the card
  * @param mci_dev MCI instance
  * @param src Where to read from to write to the card
  * @param blocknum Block number to write
@@ -140,23 +140,17 @@ static int mci_block_write(struct mci *mci, const void *src, int blocknum,
 	data.flags = MMC_DATA_WRITE;
 
 	ret = mci_send_cmd(mci, &cmd, &data);
-	if (ret)
-		return ret;
-
-	if (blocks > 1) {
-		mci_setup_cmd(&cmd,
-			MMC_CMD_STOP_TRANSMISSION,
-			0, MMC_RSP_R1b);
-			ret = mci_send_cmd(mci, &cmd, NULL);
-			if (ret)
-				return ret;
+
+	if (ret || blocks > 1) {
+		mci_setup_cmd(&cmd, MMC_CMD_STOP_TRANSMISSION, 0, MMC_RSP_R1b);
+		mci_send_cmd(mci, &cmd, NULL);
         }
 
 	return ret;
 }
 
 /**
- * Read one block of data from the card
+ * Read one or several block(s) of data from the card
  * @param mci MCI instance
  * @param dst Where to store the data read from the card
  * @param blocknum Block number to read
@@ -186,15 +180,10 @@ static int mci_read_block(struct mci *mci, void *dst, int blocknum,
 	data.flags = MMC_DATA_READ;
 
 	ret = mci_send_cmd(mci, &cmd, &data);
-	if (ret)
-		return ret;
-
-	if (blocks > 1) {
-		mci_setup_cmd(&cmd,
-			MMC_CMD_STOP_TRANSMISSION,
-			0,
-			MMC_RSP_R1b);
-			ret = mci_send_cmd(mci, &cmd, NULL);
+
+	if (ret || blocks > 1) {
+		mci_setup_cmd(&cmd, MMC_CMD_STOP_TRANSMISSION, 0, MMC_RSP_R1b);
+		mci_send_cmd(mci, &cmd, NULL);
 	}
 	return ret;
 }
-- 
1.7.5.4


_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

             reply	other threads:[~2012-02-27 22:45 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-02-27 22:45 Robert Jarzmik [this message]
2012-02-28  8:36 ` Sascha Hauer
2012-02-28 12:34   ` Robert Jarzmik
2012-02-29  7:39 ` Sascha Hauer

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1330382728-10708-1-git-send-email-robert.jarzmik@free.fr \
    --to=robert.jarzmik@free.fr \
    --cc=barebox@lists.infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox