[openwrt/openwrt] oxnas: fix qc_prep return in sata driver after kernel 4.14.200

[LEDE Commits]

hauke pushed a commit to openwrt/openwrt.git, branch openwrt-18.06:
https://git.openwrt.org/d94c59f7ebaddf3ea041d4a8eb1687e7709437df

commit d94c59f7ebaddf3ea041d4a8eb1687e7709437df
Author: Adrian Schmutzler <freifunk at adrianschmutzler.de>
AuthorDate: Fri Oct 9 16:44:30 2020 +0200

    oxnas: fix qc_prep return in sata driver after kernel 4.14.200
    
    This fixes a regression after a kernel change in 4.14.200 [1] that
    led to build failure on oxnas/ox820:
    
      drivers/ata/sata_oxnas.c:2238:13: error: initialization of
      'enum ata_completion_errors (*)(struct ata_queued_cmd *)'
      from incompatible pointer type
      'void (*)(struct ata_queued_cmd *)' [-Werror=incompatible-pointer-types]
        .qc_prep = sata_oxnas_qc_prep,
                   ^~~~~~~~~~~~~~~~~~
      drivers/ata/sata_oxnas.c:2238:13: note:
      (near initialization for 'sata_oxnas_ops.qc_prep')
    
    Our local driver is changed the same way as prototyped in the
    kernel patch, i.e. return type is changed and AC_ERR_OK return
    value is added.
    
    [1] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=306a1c5b5683c1d37565e575386139a64bdbec6f
    
    Signed-off-by: Adrian Schmutzler <freifunk at adrianschmutzler.de>
    (cherry picked from commit f6ca57e4f40528a8a0103c9f0e9647a2e11d10c3)
---
 target/linux/oxnas/files/drivers/ata/sata_oxnas.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/target/linux/oxnas/files/drivers/ata/sata_oxnas.c b/target/linux/oxnas/files/drivers/ata/sata_oxnas.c
index 64afa728a1..a54c35c8fd 100644
--- a/target/linux/oxnas/files/drivers/ata/sata_oxnas.c
+++ b/target/linux/oxnas/files/drivers/ata/sata_oxnas.c
@@ -1802,7 +1802,7 @@ static inline void sata_oxnas_reset_ucode(struct ata_host *ah, int force,
  * Prepare as much as possible for a command without involving anything that is
  * shared between ports.
  */
-static void sata_oxnas_qc_prep(struct ata_queued_cmd *qc)
+static enum ata_completion_errors sata_oxnas_qc_prep(struct ata_queued_cmd *qc)
 {
 	struct sata_oxnas_port_priv *pd;
 	int port_no = qc->ap->port_no;
@@ -1848,6 +1848,8 @@ static void sata_oxnas_qc_prep(struct ata_queued_cmd *qc)
 		/* tell it to wait */
 		iowrite32(SGDMA_CONTROL_NOGO, pd->sgdma_base + SGDMA_CONTROL);
 	}
+
+	return AC_ERR_OK;
 }
 
 static int sata_oxnas_port_start(struct ata_port *ap)