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authorCyril Bur <cyrilbur@gmail.com>2017-11-03 13:41:46 +1100
committerMichael Ellerman <mpe@ellerman.id.au>2017-11-06 20:39:31 +1100
commit6f469b67ff8a3ec2698ef1041229e111065013ce (patch)
treea8bd54a13158fabb6fe45eef61c86586df03b313 /drivers/mtd
parent77adbd2207e858f5923aa94e4a7d2f29f09217ed (diff)
downloadlinux-6f469b67ff8a3ec2698ef1041229e111065013ce.tar.bz2
mtd: powernv_flash: Use opal_async_wait_response_interruptible()
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> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'drivers/mtd')
-rw-r--r--drivers/mtd/devices/powernv_flash.c57
1 files 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;