OPAL can only manage one flash access at a time and will return an OPAL_BUSY error for each concurrent access to the flash. The simplest way to prevent this from happening is with a mutex.
Signed-off-by: Cyril Bur <cyril...@gmail.com> --- This is to address https://github.com/open-power/skiboot/issues/80 drivers/mtd/devices/powernv_flash.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/mtd/devices/powernv_flash.c b/drivers/mtd/devices/powernv_flash.c index a9a20c00687c..7b41af06f4fe 100644 --- a/drivers/mtd/devices/powernv_flash.c +++ b/drivers/mtd/devices/powernv_flash.c @@ -38,6 +38,7 @@ struct powernv_flash { struct mtd_info mtd; + struct mutex lock; u32 id; }; @@ -59,12 +60,15 @@ static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op, dev_dbg(dev, "%s(op=%d, offset=0x%llx, len=%zu)\n", __func__, op, offset, len); + mutex_lock(&info->lock); + token = opal_async_get_token_interruptible(); if (token < 0) { if (token != -ERESTARTSYS) dev_err(dev, "Failed to get an async token\n"); - return token; + rc = token; + goto out; } switch (op) { @@ -79,18 +83,21 @@ static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op, break; default: WARN_ON_ONCE(1); - return -EIO; + rc = -EIO; + goto out; } if (rc != OPAL_ASYNC_COMPLETION) { dev_err(dev, "opal_flash_async_op(op=%d) failed (rc %d)\n", op, rc); opal_async_release_token(token); - return -EIO; + rc = -EIO; + goto out; } rc = opal_async_wait_response(token, &msg); opal_async_release_token(token); + mutex_unlock(&info->lock); if (rc) { dev_err(dev, "opal async wait failed (rc %d)\n", rc); return -EIO; @@ -106,6 +113,9 @@ static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op, } return rc; +out: + mutex_unlock(&info->lock); + return rc; } /** @@ -237,6 +247,8 @@ static int powernv_flash_probe(struct platform_device *pdev) if (ret) goto out; + mutex_init(&data->lock); + dev_set_drvdata(dev, data); /* -- 2.13.0
