From 001aac257cf8adbe90cdcba6e07f8d12dfc8fa6b Mon Sep 17 00:00:00 2001 From: James Bottomley Date: Sun, 2 Dec 2007 19:10:40 +0200 Subject: [SCSI] sd,sr: add early detection of medium not present The current scsi_test_unit_ready() is updated to return sense code information (in struct scsi_sense_hdr). The sd and sr drivers are changed to interpret the sense code return asc 0x3a as no media and adjust the device status accordingly. Signed-off-by: James Bottomley --- drivers/scsi/scsi_lib.c | 46 ++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 38 insertions(+), 8 deletions(-) (limited to 'drivers/scsi/scsi_lib.c') diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index aa17e718666..db52222885b 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1973,27 +1973,57 @@ scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, } EXPORT_SYMBOL(scsi_mode_sense); +/** + * scsi_test_unit_ready - test if unit is ready + * @sdev: scsi device to change the state of. + * @timeout: command timeout + * @retries: number of retries before failing + * @sshdr_external: Optional pointer to struct scsi_sense_hdr for + * returning sense. Make sure that this is cleared before passing + * in. + * + * Returns zero if unsuccessful or an error if TUR failed. For + * removable media, a return of NOT_READY or UNIT_ATTENTION is + * translated to success, with the ->changed flag updated. + **/ int -scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries) +scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, + struct scsi_sense_hdr *sshdr_external) { char cmd[] = { TEST_UNIT_READY, 0, 0, 0, 0, 0, }; - struct scsi_sense_hdr sshdr; + struct scsi_sense_hdr *sshdr; int result; - - result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, &sshdr, - timeout, retries); + + if (!sshdr_external) + sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL); + else + sshdr = sshdr_external; + + /* try to eat the UNIT_ATTENTION if there are enough retries */ + do { + result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr, + timeout, retries); + } while ((driver_byte(result) & DRIVER_SENSE) && + sshdr && sshdr->sense_key == UNIT_ATTENTION && + --retries); + + if (!sshdr) + /* could not allocate sense buffer, so can't process it */ + return result; if ((driver_byte(result) & DRIVER_SENSE) && sdev->removable) { - if ((scsi_sense_valid(&sshdr)) && - ((sshdr.sense_key == UNIT_ATTENTION) || - (sshdr.sense_key == NOT_READY))) { + if ((scsi_sense_valid(sshdr)) && + ((sshdr->sense_key == UNIT_ATTENTION) || + (sshdr->sense_key == NOT_READY))) { sdev->changed = 1; result = 0; } } + if (!sshdr_external) + kfree(sshdr); return result; } EXPORT_SYMBOL(scsi_test_unit_ready); -- cgit v1.2.3