use HPI to interrupt background operations

From 8d2cf8e4b890a3ef0c7b63da57b8b184ab64725d Mon Sep 17 00:00:00 2001

From 8d2cf8e4b890a3ef0c7b63da57b8b184ab64725d Mon Sep 17 00:00:00 2001
From: Chuanxiao Dong <[email protected]>
Date: Tue, 23 Nov 2010 12:01:58 +0800
Subject: [PATCH 4/4] mmc: Add HPI operation to interrupt BKOPS

Before start a new user request, driver need to wait until the BKOPS finished, or use HPI to interrupt the BKOPS since user request has a higher priority than BKOPS.

This patch implemented using HPI to interrupt BKOPS if eMMC card supports HPI.

Signed-off-by Chuanxiao Dong <[email protected]>

---
 drivers/mmc/core/core.c |   51 ++++++++++++++++++++++++++++++++++++++++++++++-

 1 files changed, 50 insertions(+), 1 deletions(-)

drivers/mmc/core/core.c +20 -0

index 6891169..644ce9d 100644
@@ -202,6 +202,50 @@ static void mmc_wait_done(struct mmc_request *mrq)
  }
 
  /**
+ *     mmc_issue_hpi_cmd - start a hpi to interrupt background
+ *     operations
+ *     @card: MMC card need to interrupt
+ *
+ *  start MMC_SEND_STATUS/MMC_STOP_TRANSMISSION to stop the
+ *  background operations.
+ *
+ *  return value:
+ *  0: successfully interrupt BKOPS
+ *  -EINVAL: HPI command invalid
+ *  -EIO: failed when interrupt BKOPS
+ */
+static int mmc_issue_hpi_cmd(struct mmc_card *card)
+{
+       struct mmc_command cmd;
+       unsigned int opcode;
+       unsigned int flags;
+       int err;
+
+       opcode = card->ext_csd.hpi_cmd;

drivers/mmc/core/core.c +20 -2

+       err = mmc_wait_for_cmd(card->host, &cmd, 0);
+       if (err || (cmd.resp[0] & 0xFDF92000)) {
+               printk(KERN_ERR "error %d requesting status %#x\n",
+                       err, cmd.resp[0]);
+               /*
+                * abandon this BKOPS, let block layer handle
+                * this
+                */
+               return -EIO;
+       }
+       return 0;
+}
+
+/**
  *     mmc_wait_for_bkops- start a bkops check and wait for
  *     completion
  *     @card: MMC card need to check

@@ -224,9 +268,14 @@ retry:
 
        if (card->ext_csd.hpi_en) {
                /*
-                * TODO
                 * HPI to interrupt BKOPS if supported
                 */
+               err = mmc_issue_hpi_cmd(card);
+               if (err == -EINVAL) {
+                       /* disable HPI feature */
+                       card->ext_csd.hpi_en = 0;
+                       goto retry;
+               }
        } else {
                memset(&cmd, 0, sizeof(struct mmc_command));
 
--

1.6.6.1

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Quoted 11 lines

+       opcode = card->ext_csd.hpi_cmd;
+       if (opcode == MMC_STOP_TRANSMISSION)
+               flags = MMC_RSP_R1B | MMC_CMD_AC;
+       else if (opcode == MMC_SEND_STATUS)
+               flags = MMC_RSP_R1 | MMC_CMD_AC;
+       else
+               return -EINVAL;
+
+       memset(&cmd, 0, sizeof(struct mmc_command));
+       cmd.opcode = opcode;
+       cmd.arg = card->rca << 16 | 1;

Maybe missing set the flags;

            cmd.flags = flags;

Thank you,
Kyungmin Park