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Date:      Sat, 15 Feb 2014 20:45:53 +0000 (UTC)
From:      Ian Lepore <ian@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r261945 - head/sys/dev/sdhci
Message-ID:  <201402152045.s1FKjr8v003607@svn.freebsd.org>
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Author: ian
Date: Sat Feb 15 20:45:53 2014
New Revision: 261945
URL: http://svnweb.freebsd.org/changeset/base/261945

Log:
  Add timeout logic to sdhci, separate from the timeouts done by the hardware.
  
  If the hardware is not in a good state (like maybe clocks aren't running
  because of a configuration glitch) its timeout clock may also not work
  correctly, and the next command sent will hang that thread forever.  The
  thread in question is usually the one and only thread (at init time) or
  a bio queue worker thread whose lockup will eventually lead to the whole
  system locking up when it runs out of buffers.
  
  No sd card command should take longer than 250ms.  This new code establishes
  a 1-second timeout to allow plenty of safety margin over that.

Modified:
  head/sys/dev/sdhci/sdhci.c
  head/sys/dev/sdhci/sdhci.h

Modified: head/sys/dev/sdhci/sdhci.c
==============================================================================
--- head/sys/dev/sdhci/sdhci.c	Sat Feb 15 20:36:54 2014	(r261944)
+++ head/sys/dev/sdhci/sdhci.c	Sat Feb 15 20:45:53 2014	(r261945)
@@ -29,6 +29,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/bus.h>
+#include <sys/callout.h>
 #include <sys/conf.h>
 #include <sys/kernel.h>
 #include <sys/lock.h>
@@ -609,6 +610,7 @@ sdhci_init_slot(device_t dev, struct sdh
 	
 	TASK_INIT(&slot->card_task, 0, sdhci_card_task, slot);
 	callout_init(&slot->card_callout, 1);
+	callout_init_mtx(&slot->timeout_callout, &slot->mtx, 0);
 	return (0);
 }
 
@@ -623,6 +625,7 @@ sdhci_cleanup_slot(struct sdhci_slot *sl
 {
 	device_t d;
 
+	callout_drain(&slot->timeout_callout);
 	callout_drain(&slot->card_callout);
 	taskqueue_drain(taskqueue_swi_giant, &slot->card_task);
 
@@ -702,6 +705,32 @@ sdhci_generic_update_ios(device_t brdev,
 	return (0);
 }
 
+static void 
+sdhci_req_done(struct sdhci_slot *slot)
+{
+	struct mmc_request *req;
+
+	if (slot->req != NULL && slot->curcmd != NULL) {
+		callout_stop(&slot->timeout_callout);
+		req = slot->req;
+		slot->req = NULL;
+		slot->curcmd = NULL;
+		req->done(req);
+	}
+}
+ 
+static void 
+sdhci_timeout(void *arg)
+{
+	struct sdhci_slot *slot = arg;
+
+	if (slot->curcmd != NULL) {
+		sdhci_reset(slot, SDHCI_RESET_ALL);
+		slot->curcmd->error = MMC_ERR_TIMEOUT;
+		sdhci_req_done(slot);
+	}
+}
+ 
 static void
 sdhci_set_transfer_mode(struct sdhci_slot *slot,
 	struct mmc_data *data)
@@ -727,7 +756,6 @@ sdhci_set_transfer_mode(struct sdhci_slo
 static void
 sdhci_start_command(struct sdhci_slot *slot, struct mmc_command *cmd)
 {
-	struct mmc_request *req = slot->req;
 	int flags, timeout;
 	uint32_t mask, state;
 
@@ -740,9 +768,7 @@ sdhci_start_command(struct sdhci_slot *s
 	if ((cmd->flags & MMC_RSP_136) && (cmd->flags & MMC_RSP_BUSY)) {
 		slot_printf(slot, "Unsupported response type!\n");
 		cmd->error = MMC_ERR_FAILED;
-		slot->req = NULL;
-		slot->curcmd = NULL;
-		req->done(req);
+		sdhci_req_done(slot);
 		return;
 	}
 
@@ -754,9 +780,7 @@ sdhci_start_command(struct sdhci_slot *s
 	    slot->power == 0 ||
 	    slot->clock == 0) {
 		cmd->error = MMC_ERR_FAILED;
-		slot->req = NULL;
-		slot->curcmd = NULL;
-		req->done(req);
+		sdhci_req_done(slot);
 		return;
 	}
 	/* Always wait for free CMD bus. */
@@ -784,9 +808,7 @@ sdhci_start_command(struct sdhci_slot *s
 			    "inhibit bit(s).\n");
 			sdhci_dumpregs(slot);
 			cmd->error = MMC_ERR_FAILED;
-			slot->req = NULL;
-			slot->curcmd = NULL;
-			req->done(req);
+			sdhci_req_done(slot);
 			return;
 		}
 		timeout--;
@@ -828,6 +850,8 @@ sdhci_start_command(struct sdhci_slot *s
 	sdhci_set_transfer_mode(slot, cmd->data);
 	/* Start command. */
 	WR2(slot, SDHCI_COMMAND_FLAGS, (cmd->opcode << 8) | (flags & 0xff));
+	/* Start timeout callout; no command should take more than a second. */
+	callout_reset(&slot->timeout_callout, hz, sdhci_timeout, slot);
 }
 
 static void
@@ -1013,10 +1037,7 @@ sdhci_start(struct sdhci_slot *slot)
 		sdhci_reset(slot, SDHCI_RESET_DATA);
 	}
 
-	/* We must be done -- bad idea to do this while locked? */
-	slot->req = NULL;
-	slot->curcmd = NULL;
-	req->done(req);
+	sdhci_req_done(slot);
 }
 
 int

Modified: head/sys/dev/sdhci/sdhci.h
==============================================================================
--- head/sys/dev/sdhci/sdhci.h	Sat Feb 15 20:36:54 2014	(r261944)
+++ head/sys/dev/sdhci/sdhci.h	Sat Feb 15 20:45:53 2014	(r261945)
@@ -241,6 +241,7 @@ struct sdhci_slot {
 	bus_addr_t	paddr;		/* DMA buffer address */
 	struct task	card_task;	/* Card presence check task */
 	struct callout	card_callout;	/* Card insert delay callout */
+	struct callout	timeout_callout;/* Card command/data response timeout */
 	struct mmc_host host;		/* Host parameters */
 	struct mmc_request *req;	/* Current request */
 	struct mmc_command *curcmd;	/* Current command of current request */

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