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authorDavid Brown <davidb@codeaurora.org>2011-03-16 22:13:16 -0700
committerDavid Brown <davidb@codeaurora.org>2011-03-16 22:13:16 -0700
commit92c260f755c42337c550d8ac1f8ccd1b32bffb20 (patch)
tree6d04fefc1adeecabfb2b00c201e0db78fa2b5529 /drivers/s390/char/tape_34xx.c
parent8e76a80960bf06c245160a484d5a363ca6b520bb (diff)
parent05e34754518b6a90d5c392790c032575fab12d66 (diff)
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Merge remote branch 'rmk/for-linus' into for-linus
* rmk/for-linus: (1557 commits) ARM: 6806/1: irq: introduce entry and exit functions for chained handlers ARM: 6781/1: Thumb-2: Work around buggy Thumb-2 short branch relocations in gas ARM: 6747/1: P2V: Thumb2 support ARM: 6798/1: aout-core: zero thread debug registers in a.out core dump ARM: 6796/1: Footbridge: Fix I/O mappings for NOMMU mode ARM: 6784/1: errata: no automatic Store Buffer drain on Cortex-A9 ARM: 6772/1: errata: possible fault MMU translations following an ASID switch ARM: 6776/1: mach-ux500: activate fix for errata 753970 ARM: 6794/1: SPEAr: Append UL to device address macros. ARM: 6793/1: SPEAr: Remove unused *_SIZE macros from spear*.h files ARM: 6792/1: SPEAr: Replace SIZE macro's with SZ_4K macros ARM: 6791/1: SPEAr3xx: Declare device structures after shirq code ARM: 6790/1: SPEAr: Clock Framework: Rename usbd clock and align apb_clk entry ARM: 6789/1: SPEAr3xx: Rename sdio to sdhci ARM: 6788/1: SPEAr: Include mach/hardware.h instead of mach/spear.h ARM: 6787/1: SPEAr: Reorder #includes in .h & .c files. ARM: 6681/1: SPEAr: add debugfs support to clk API ARM: 6703/1: SPEAr: update clk API support ARM: 6679/1: SPEAr: make clk API functions more generic ARM: 6737/1: SPEAr: formalized timer support ... Conflicts: arch/arm/mach-msm/board-msm7x27.c arch/arm/mach-msm/board-msm7x30.c arch/arm/mach-msm/board-qsd8x50.c arch/arm/mach-msm/board-sapphire.c arch/arm/mach-msm/include/mach/memory.h
Diffstat (limited to 'drivers/s390/char/tape_34xx.c')
-rw-r--r--drivers/s390/char/tape_34xx.c59
1 files changed, 41 insertions, 18 deletions
diff --git a/drivers/s390/char/tape_34xx.c b/drivers/s390/char/tape_34xx.c
index c17f35b..c265111 100644
--- a/drivers/s390/char/tape_34xx.c
+++ b/drivers/s390/char/tape_34xx.c
@@ -53,23 +53,11 @@ static void tape_34xx_delete_sbid_from(struct tape_device *, int);
* Medium sense for 34xx tapes. There is no 'real' medium sense call.
* So we just do a normal sense.
*/
-static int
-tape_34xx_medium_sense(struct tape_device *device)
+static void __tape_34xx_medium_sense(struct tape_request *request)
{
- struct tape_request *request;
- unsigned char *sense;
- int rc;
-
- request = tape_alloc_request(1, 32);
- if (IS_ERR(request)) {
- DBF_EXCEPTION(6, "MSEN fail\n");
- return PTR_ERR(request);
- }
-
- request->op = TO_MSEN;
- tape_ccw_end(request->cpaddr, SENSE, 32, request->cpdata);
+ struct tape_device *device = request->device;
+ unsigned char *sense;
- rc = tape_do_io_interruptible(device, request);
if (request->rc == 0) {
sense = request->cpdata;
@@ -88,15 +76,47 @@ tape_34xx_medium_sense(struct tape_device *device)
device->tape_generic_status |= GMT_WR_PROT(~0);
else
device->tape_generic_status &= ~GMT_WR_PROT(~0);
- } else {
+ } else
DBF_EVENT(4, "tape_34xx: medium sense failed with rc=%d\n",
request->rc);
- }
tape_free_request(request);
+}
+
+static int tape_34xx_medium_sense(struct tape_device *device)
+{
+ struct tape_request *request;
+ int rc;
+
+ request = tape_alloc_request(1, 32);
+ if (IS_ERR(request)) {
+ DBF_EXCEPTION(6, "MSEN fail\n");
+ return PTR_ERR(request);
+ }
+ request->op = TO_MSEN;
+ tape_ccw_end(request->cpaddr, SENSE, 32, request->cpdata);
+ rc = tape_do_io_interruptible(device, request);
+ __tape_34xx_medium_sense(request);
return rc;
}
+static void tape_34xx_medium_sense_async(struct tape_device *device)
+{
+ struct tape_request *request;
+
+ request = tape_alloc_request(1, 32);
+ if (IS_ERR(request)) {
+ DBF_EXCEPTION(6, "MSEN fail\n");
+ return;
+ }
+
+ request->op = TO_MSEN;
+ tape_ccw_end(request->cpaddr, SENSE, 32, request->cpdata);
+ request->callback = (void *) __tape_34xx_medium_sense;
+ request->callback_data = NULL;
+ tape_do_io_async(device, request);
+}
+
struct tape_34xx_work {
struct tape_device *device;
enum tape_op op;
@@ -109,6 +129,9 @@ struct tape_34xx_work {
* is inserted but cannot call tape_do_io* from an interrupt context.
* Maybe that's useful for other actions we want to start from the
* interrupt handler.
+ * Note: the work handler is called by the system work queue. The tape
+ * commands started by the handler need to be asynchrounous, otherwise
+ * a deadlock can occur e.g. in case of a deferred cc=1 (see __tape_do_irq).
*/
static void
tape_34xx_work_handler(struct work_struct *work)
@@ -119,7 +142,7 @@ tape_34xx_work_handler(struct work_struct *work)
switch(p->op) {
case TO_MSEN:
- tape_34xx_medium_sense(device);
+ tape_34xx_medium_sense_async(device);
break;
default:
DBF_EVENT(3, "T34XX: internal error: unknown work\n");