On Sun, Jan 02, 2022 at 11:23:45PM +0000, Maciej W. Rozycki wrote:
> Allow SCSI hosts to request avoiding trailing allocation length with VPD
> inquiries, and use the mechanism to work around an issue with at least
> some BusLogic MultiMaster host bus adapters and observed with the BT-958
> model specifically where issuing commands that return less data than
> provided for causes fatal failures:
Wouldn't it make more sesnse to hide this quirk insde of
scsi_vpd_inquiry to also handle the scsi_get_vpd_buf case? Something
like:
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 211aace69c22c..194a51f772aaa 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -289,8 +289,8 @@ EXPORT_SYMBOL(scsi_track_queue_full);
*
* Returns size of the vpd page on success or a negative error number.
*/
-static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
- u8 page, unsigned len)
+static int __scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
+ u8 page, unsigned len)
{
int result;
unsigned char cmd[16];
@@ -321,6 +321,20 @@ static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
return get_unaligned_be16(&buffer[2]) + 4;
}
+static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
+ u8 page, unsigned len)
+{
+ if (sdev->host->no_trailing_allocation_length) {
+ int ret = __scsi_vpd_inquiry(sdev, buffer, page, min(4U, len));
+
+ if (ret < 4)
+ return ret;
+ len = min_t(unsigned int, ret, len);
+ }
+
+ return __scsi_vpd_inquiry(sdev, buffer, page, len);
+}
+
/**
* scsi_get_vpd_page - Get Vital Product Data from a SCSI device
* @sdev: The device to ask
