From: Cyril Bur <cyrilbur@gmail.com>
To: linux-mtd@lists.infradead.org, linuxppc-dev@lists.ozlabs.org,
stewart@linux.vnet.ibm.com
Cc: dwmw2@infradead.org, computersforpeace@gmail.com,
boris.brezillon@free-electrons.com, sjitindarsingh@gmail.com
Subject: [PATCH v5 10/10] mtd: powernv_flash: Use opal_async_wait_response_interruptible()
Date: Fri, 3 Nov 2017 13:41:46 +1100 [thread overview]
Message-ID: <20171103024146.17086-11-cyrilbur@gmail.com> (raw)
In-Reply-To: <20171103024146.17086-1-cyrilbur@gmail.com>
The OPAL calls performed in this driver shouldn't be using
opal_async_wait_response() as this performs a wait_event() which, on
long running OPAL calls could result in hung task warnings. wait_event()
prevents timely signal delivery which is also undesirable.
This patch also attempts to quieten down the use of dev_err() when
errors haven't actually occurred and also to return better information up
the stack rather than always -EIO.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
drivers/mtd/devices/powernv_flash.c | 57 +++++++++++++++++++++++--------------
1 file changed, 35 insertions(+), 22 deletions(-)
diff --git a/drivers/mtd/devices/powernv_flash.c b/drivers/mtd/devices/powernv_flash.c
index 3343d4f5c4f3..26f9feaa5d17 100644
--- a/drivers/mtd/devices/powernv_flash.c
+++ b/drivers/mtd/devices/powernv_flash.c
@@ -89,33 +89,46 @@ static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op,
return -EIO;
}
- if (rc == OPAL_SUCCESS)
- goto out_success;
+ if (rc == OPAL_ASYNC_COMPLETION) {
+ rc = opal_async_wait_response_interruptible(token, &msg);
+ if (rc) {
+ /*
+ * If we return the mtd core will free the
+ * buffer we've just passed to OPAL but OPAL
+ * will continue to read or write from that
+ * memory.
+ * It may be tempting to ultimately return 0
+ * if we're doing a read or a write since we
+ * are going to end up waiting until OPAL is
+ * done. However, because the MTD core sends
+ * us the userspace request in chunks, we need
+ * it to know we've been interrupted.
+ */
+ rc = -EINTR;
+ if (opal_async_wait_response(token, &msg))
+ dev_err(dev, "opal_async_wait_response() failed\n");
+ goto out;
+ }
+ rc = opal_get_async_rc(msg);
+ }
- if (rc != OPAL_ASYNC_COMPLETION) {
+ /*
+ * OPAL does mutual exclusion on the flash, it will return
+ * OPAL_BUSY.
+ * During firmware updates by the service processor OPAL may
+ * be (temporarily) prevented from accessing the flash, in
+ * this case OPAL will also return OPAL_BUSY.
+ * Both cases aren't errors exactly but the flash could have
+ * changed, userspace should be informed.
+ */
+ if (rc != OPAL_SUCCESS && rc != OPAL_BUSY)
dev_err(dev, "opal_flash_async_op(op=%d) failed (rc %d)\n",
op, rc);
- rc = -EIO;
- goto out;
- }
- rc = opal_async_wait_response(token, &msg);
- if (rc) {
- dev_err(dev, "opal async wait failed (rc %d)\n", rc);
- rc = -EIO;
- goto out;
- }
-
- rc = opal_get_async_rc(msg);
-out_success:
- if (rc == OPAL_SUCCESS) {
- rc = 0;
- if (retlen)
- *retlen = len;
- } else {
- rc = -EIO;
- }
+ if (rc == OPAL_SUCCESS && retlen)
+ *retlen = len;
+ rc = opal_error_code(rc);
out:
opal_async_release_token(token);
return rc;
--
2.15.0
prev parent reply other threads:[~2017-11-03 2:42 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-03 2:41 [PATCH v5 00/10] Allow opal-async waiters to get interrupted Cyril Bur
2017-11-03 2:41 ` [PATCH v5 01/10] mtd: powernv_flash: Use WARN_ON_ONCE() rather than BUG_ON() Cyril Bur
2017-11-07 23:30 ` [v5, " Michael Ellerman
2017-11-03 2:41 ` [PATCH v5 02/10] mtd: powernv_flash: Don't treat OPAL_SUCCESS as an error Cyril Bur
2017-11-03 2:41 ` [PATCH v5 03/10] mtd: powernv_flash: Remove pointless goto in driver init Cyril Bur
2017-11-03 2:41 ` [PATCH v5 04/10] mtd: powernv_flash: Don't return -ERESTARTSYS on interrupted token acquisition Cyril Bur
2017-11-03 2:41 ` [PATCH v5 05/10] powerpc/opal: Make __opal_async_{get, release}_token() static Cyril Bur
2017-11-03 2:41 ` [PATCH v5 06/10] powerpc/opal: Rework the opal-async interface Cyril Bur
2017-11-06 9:41 ` Michael Ellerman
2017-11-06 23:38 ` Cyril Bur
2017-11-03 2:41 ` [PATCH v5 07/10] powernv/opal-sensor: remove not needed lock Cyril Bur
2017-11-03 2:41 ` [PATCH v5 08/10] powerpc/opal: Add opal_async_wait_response_interruptible() to opal-async Cyril Bur
2017-11-03 2:41 ` [PATCH v5 09/10] powerpc/powernv: Add OPAL_BUSY to opal_error_code() Cyril Bur
2017-11-03 2:41 ` Cyril Bur [this message]
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