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authorAlexander Usyskin <alexander.usyskin@intel.com>2016-01-07 14:46:37 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-02-06 22:06:43 -0800
commit8b2458f413c429e4c5c4799e02ec2820396aaac4 (patch)
tree2c1c8ec69d5f1176c10e465ead021c834b63e3cc /drivers/misc/mei
parent13cf988562b0c7f06e0016bea2b5304358397702 (diff)
downloadlinux-8b2458f413c429e4c5c4799e02ec2820396aaac4.tar.bz2
mei: always copy the read buffer if data is ready
Copy completed callback content to the user space if we have such callback ready in the beginning of the read. Simplify offset processing logic as byproduct. This is a refinement for: commit 139aacf757fc ("mei: fix read after read scenario") Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc/mei')
-rw-r--r--drivers/misc/mei/main.c32
1 files changed, 14 insertions, 18 deletions
diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index 677d0362f334..36ca15234344 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -159,27 +159,22 @@ static ssize_t mei_read(struct file *file, char __user *ubuf,
goto out;
}
+ if (ubuf == NULL) {
+ rets = -EMSGSIZE;
+ goto out;
+ }
+
if (cl == &dev->iamthif_cl) {
rets = mei_amthif_read(dev, file, ubuf, length, offset);
goto out;
}
cb = mei_cl_read_cb(cl, file);
- if (cb) {
- /* read what left */
- if (cb->buf_idx > *offset)
- goto copy_buffer;
- /* offset is beyond buf_idx we have no more data return 0 */
- if (cb->buf_idx > 0 && cb->buf_idx <= *offset) {
- rets = 0;
- goto free;
- }
- /* Offset needs to be cleaned for contiguous reads*/
- if (cb->buf_idx == 0 && *offset > 0)
- *offset = 0;
- } else if (*offset > 0) {
+ if (cb)
+ goto copy_buffer;
+
+ if (*offset > 0)
*offset = 0;
- }
err = mei_cl_read_start(cl, length, file);
if (err && err != -EBUSY) {
@@ -231,10 +226,10 @@ copy_buffer:
goto free;
}
- cl_dbg(dev, cl, "buf.size = %d buf.idx = %ld\n",
- cb->buf.size, cb->buf_idx);
- if (length == 0 || ubuf == NULL || *offset > cb->buf_idx) {
- rets = -EMSGSIZE;
+ cl_dbg(dev, cl, "buf.size = %d buf.idx = %ld offset = %lld\n",
+ cb->buf.size, cb->buf_idx, *offset);
+ if (*offset >= cb->buf_idx) {
+ rets = 0;
goto free;
}
@@ -255,6 +250,7 @@ copy_buffer:
free:
mei_io_cb_free(cb);
+ *offset = 0;
out:
cl_dbg(dev, cl, "end mei read rets = %d\n", rets);