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 <cyril...@gmail.com> --- drivers/mtd/devices/powernv_flash.c | 28 +++++++++++++++++++++++----- 1 file changed, 23 insertions(+), 5 deletions(-) diff --git a/drivers/mtd/devices/powernv_flash.c b/drivers/mtd/devices/powernv_flash.c index d7243b72ba6e..cfa274ba7e40 100644 --- a/drivers/mtd/devices/powernv_flash.c +++ b/drivers/mtd/devices/powernv_flash.c @@ -90,16 +90,34 @@ static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op, goto out_success; if (rc != OPAL_ASYNC_COMPLETION) { - dev_err(dev, "opal_flash_async_op(op=%d) failed (rc %d)\n", + if (rc != OPAL_BUSY) + dev_err(dev, "opal_flash_async_op(op=%d) failed (rc %d)\n", op, rc); - rc = -EIO; + rc = opal_error_code(rc); goto out; } - rc = opal_async_wait_response(token, &msg); + rc = opal_async_wait_response_interruptible(token, &msg); if (rc) { - dev_err(dev, "opal async wait failed (rc %d)\n", rc); - rc = -EIO; + /* + * Awkward, we've been interrupted but we cannot return. If we + * do 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. + * Future work will introduce a call to tell OPAL to stop + * using the buffer. + * 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 must report EINTR so that + * it doesn't just send us the next chunk, thus defeating the + * point of the _interruptible wait. + */ + rc = -EINTR; + if (op == FLASH_OP_READ || op == FLASH_OP_WRITE) { + if (opal_async_wait_response(token, &msg)) + dev_err(dev, "opal async wait failed (rc %d)\n", rc); + } goto out; } -- 2.13.2