From a7e6de544c5c238a06935c96d27151432c94d2e6 Mon Sep 17 00:00:00 2001 From: Christian Lamparter Date: Tue, 26 Apr 2016 12:03:03 +0300 Subject: [PATCH] ata: sata_dwc_460ex: fix crash on offline links without an attached drive This patch fixes Machine Check "Data Write PLB Error" which happens when libata-sff's ata_sff_dev_select is trying to write into the device_addr in order to select a drive. However, SATA has no master or slave devices like the old ATA Bus, therefore selecting a different drive is kind of pointless. Data Write PLB Error Oops: Machine check, sig: 7 [#1] PowerPC 44x Platform Modules linked in: CPU: 0 PID: 508 Comm: scsi_eh_0 Not tainted 4.6.0-rc3-next-20160412+ #10 [...] NIP [c027e820] ata_sff_dev_select+0x3c/0x44 LR [c027e810] ata_sff_dev_select+0x2c/0x44 Call Trace: [cec31cd0] [c027da00] ata_sff_postreset+0x40/0xb4 (unreliable) [cec31ce0] [c027a03c] ata_eh_reset+0x5cc/0x928 [cec31d60] [c027a840] ata_eh_recover+0x330/0x10bc [cec31df0] [c027bae0] ata_do_eh+0x4c/0xa4 [...] Signed-off-by: Christian Lamparter Signed-off-by: Tejun Heo --- drivers/ata/sata_dwc_460ex.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/ata/sata_dwc_460ex.c b/drivers/ata/sata_dwc_460ex.c index 5213e2205606..7f953892647a 100644 --- a/drivers/ata/sata_dwc_460ex.c +++ b/drivers/ata/sata_dwc_460ex.c @@ -1134,6 +1134,11 @@ static int sata_dwc_hardreset(struct ata_link *link, unsigned int *class, return ret; } +static void sata_dwc_dev_select(struct ata_port *ap, unsigned int device) +{ + /* SATA DWC is master only */ +} + /* * scsi mid-layer and libata interface structures */ @@ -1164,6 +1169,8 @@ static struct ata_port_operations sata_dwc_ops = { .port_start = sata_dwc_port_start, .port_stop = sata_dwc_port_stop, + .sff_dev_select = sata_dwc_dev_select, + .bmdma_setup = sata_dwc_bmdma_setup, .bmdma_start = sata_dwc_bmdma_start, }; -- 2.20.1