[SCSI] sd: Reduce buffer size for vpd request

Somehow older areca firmware versions have issues with
scsi_get_vpd_page() and a large buffer, the firmware
seems to crash and the scsi error-handler will start endless
recovery retries.
Limiting the buf-size to 64-bytes fixes this issue with older
firmware versions (<1.49 for my controller).

Fixes a regression with areca controllers and older firmware versions
introduced by commit: 66c28f97120e8a621afd5aa7a31c4b85c547d33d

Reported-by: Nix <nix@esperi.org.uk>
Tested-by: Nix <nix@esperi.org.uk>
Signed-off-by: Bernd Schubert <bernd.schubert@itwm.fraunhofer.de>
Cc: stable@vger.kernel.org # delay inclusion for 2 months for testing
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 5693f6d7eddb8b20cd9b3e0374a4e73e60ab7aa2..ab96b793f9041d0828b5ce2c0de1d452d64f4f93 100644 (file)
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2639,13 +2639,16 @@ static void sd_read_write_same(struct scsi_disk *sdkp, unsigned char *buffer)
        struct scsi_device *sdev = sdkp->device;
 
        if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, INQUIRY) < 0) {
+               /* too large values might cause issues with arcmsr */
+               int vpd_buf_len = 64;
+
                sdev->no_report_opcodes = 1;
 
                /* Disable WRITE SAME if REPORT SUPPORTED OPERATION
                 * CODES is unsupported and the device has an ATA
                 * Information VPD page (SAT).
                 */
-               if (!scsi_get_vpd_page(sdev, 0x89, buffer, SD_BUF_SIZE))
+               if (!scsi_get_vpd_page(sdev, 0x89, buffer, vpd_buf_len))
                        sdev->no_write_same = 1;
        }