another SCSI bug fix for 2.6.24-rc7

This one's a fatal bug in the qla1280 32 bit descriptor handling, since the unitialised req_cnt variable is used to count the number of descriptor slots. It turns out that qla1280 only uses 32 bit descriptors on x86 if HIGHMEM isn't enabled, which is why it's taken so long to find someone with a configuration that actually saw the problem.

The patch is available from:

master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6.git

I've also attached it below for convenience.

James

---

From: FUJITA Tomonori <[email protected]>
Date: Tue, 8 Jan 2008 23:07:01 +0900
Subject: [SCSI] qla1280: fix 32 bit segment code

There's an error remaining in the 32 bit descriptor code after the conversion to dma accessors: req_cnt is left uninitialised.

qla1280_32bit_start_scsi gives the following warnings:

drivers/scsi/qla1280.c: In function 'qla1280_32bit_start_scsi':
drivers/scsi/qla1280.c:3044: warning: unused variable 'dma_handle' drivers/scsi/qla1280.c: In function 'qla1280_queuecommand':
drivers/scsi/qla1280.c:3060: warning: 'req_cnt' is used uninitialized in this function drivers/scsi/qla1280.c:3042: note: 'req_cnt' was declared here

---
 drivers/scsi/qla1280.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

index 146d540..2886407 100644
@@ -3041,7 +3041,6 @@ qla1280_32bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
 	int cnt;
 	int req_cnt;
 	int seg_cnt;
-	dma_addr_t dma_handle;
 	u8 dir;
 
 	ENTER("qla1280_32bit_start_scsi");

@@ -3050,6 +3049,7 @@ qla1280_32bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
 		cmd->cmnd[0]);
 
 	/* Calculate number of entries and segments required. */
+	req_cnt = 1;
 	seg_cnt = scsi_dma_map(cmd);
 	if (seg_cnt) {
 		/*

1.5.3.7