[PATCH 4/4] ses: make page2 support optional

[Hannes Reinecke]

Simple subenclosures do not need to support SES page 2, so make
it optional.

Signed-off-by: Hannes Reinecke <h...@suse.com>
---
 drivers/scsi/ses.c | 39 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 38 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/ses.c b/drivers/scsi/ses.c
index 46984cd..c52d110 100644
--- a/drivers/scsi/ses.c
+++ b/drivers/scsi/ses.c
@@ -51,6 +51,13 @@ struct ses_component {
        u64 addr;
 };
 
+static bool ses_page2_supported(struct enclosure_device *edev)
+{
+       struct ses_device *ses_dev = edev->scratch;
+
+       return (ses_dev->page2 != NULL);
+}
+
 static int ses_probe(struct device *dev)
 {
        struct scsi_device *sdev = to_scsi_device(dev);
@@ -204,6 +211,10 @@ static void ses_get_fault(struct enclosure_device *edev,
 {
        unsigned char *desc;
 
+       if (!ses_page2_supported(edev)) {
+               ecomp->fault = 0;
+               return;
+       }
        desc = ses_get_page2_descriptor(edev, ecomp);
        if (desc)
                ecomp->fault = (desc[3] & 0x60) >> 4;
@@ -216,6 +227,9 @@ static int ses_set_fault(struct enclosure_device *edev,
        unsigned char desc[4];
        unsigned char *desc_ptr;
 
+       if (!ses_page2_supported(edev))
+               return -EINVAL;
+
        desc_ptr = ses_get_page2_descriptor(edev, ecomp);
 
        if (!desc_ptr)
@@ -243,6 +257,10 @@ static void ses_get_status(struct enclosure_device *edev,
 {
        unsigned char *desc;
 
+       if (!ses_page2_supported(edev)) {
+               ecomp->status = 0;
+               return;
+       }
        desc = ses_get_page2_descriptor(edev, ecomp);
        if (desc)
                ecomp->status = (desc[0] & 0x0f);
@@ -253,6 +271,10 @@ static void ses_get_locate(struct enclosure_device *edev,
 {
        unsigned char *desc;
 
+       if (!ses_page2_supported(edev)) {
+               ecomp->locate = 0;
+               return;
+       }
        desc = ses_get_page2_descriptor(edev, ecomp);
        if (desc)
                ecomp->locate = (desc[2] & 0x02) ? 1 : 0;
@@ -265,6 +287,9 @@ static int ses_set_locate(struct enclosure_device *edev,
        unsigned char desc[4];
        unsigned char *desc_ptr;
 
+       if (!ses_page2_supported(edev))
+               return -EINVAL;
+
        desc_ptr = ses_get_page2_descriptor(edev, ecomp);
 
        if (!desc_ptr)
@@ -293,6 +318,9 @@ static int ses_set_active(struct enclosure_device *edev,
        unsigned char desc[4];
        unsigned char *desc_ptr;
 
+       if (!ses_page2_supported(edev))
+               return -EINVAL;
+
        desc_ptr = ses_get_page2_descriptor(edev, ecomp);
 
        if (!desc_ptr)
@@ -329,6 +357,11 @@ static void ses_get_power_status(struct enclosure_device 
*edev,
 {
        unsigned char *desc;
 
+       if (!ses_page2_supported(edev)) {
+               ecomp->power_status = 0;
+               return;
+       }
+
        desc = ses_get_page2_descriptor(edev, ecomp);
        if (desc)
                ecomp->power_status = (desc[3] & 0x10) ? 0 : 1;
@@ -341,6 +374,9 @@ static int ses_set_power_status(struct enclosure_device 
*edev,
        unsigned char desc[4];
        unsigned char *desc_ptr;
 
+       if (!ses_page2_supported(edev))
+               return -EINVAL;
+
        desc_ptr = ses_get_page2_descriptor(edev, ecomp);
 
        if (!desc_ptr)
@@ -674,7 +710,7 @@ static int ses_intf_add(struct device *cdev,
        page = 2;
        result = ses_recv_diag(sdev, page, hdr_buf, INIT_ALLOC_SIZE);
        if (result)
-               goto recv_failed;
+               goto page2_not_supported;
 
        len = (hdr_buf[2] << 8) + hdr_buf[3] + 4;
        buf = kzalloc(len, GFP_KERNEL);
@@ -707,6 +743,7 @@ static int ses_intf_add(struct device *cdev,
                ses_dev->page10_len = len;
                buf = NULL;
        }
+page2_not_supported:
        scomp = kzalloc(sizeof(struct ses_component) * components, GFP_KERNEL);
        if (!scomp)
                goto err_free;
-- 
1.8.5.6