Re: [PATCH v2] advansys: fix regression with request_firmware change

[Herton Ronaldo Krzesinski <herton@mandriva.com.br>]

Em Dom 28 Mar 2010, às 12:25:20, James Bottomley escreveu:
> On Fri, 2010-03-26 at 20:05 -0300, Herton Ronaldo Krzesinski wrote:
> > On newer kernels users of advansys module are reporting system hang when
> > trying to load it without firmware files present. After looking closely
> > at description on https://qa.mandriva.com/show_bug.cgi?id=53220, I think
> > this is related to commit "[SCSI] advansys: use request_firmware". The
> > problem is that after switch to request_firmware, asc_dvc->err_code
> > isn't being set when firmware files aren't found or loading fails.
> > 
> > err_code is used by the driver to judge if there was a fatal error or
> > not, as can be seen for example on advansys_board_found, which will only
> > return -ENODEV when err_code is set. Because err_code isn't being set
> > when request_firmware fails, this is a change of behaviour of the code
> > before request_firmware addition, making it continue to load and it
> > fails later as the firmware wasn't really loaded.
> > 
> > Also, error handling on advansys_board_found is fixed, because it's
> > buggy in the case we have an ASC_NARROW_BOARD set and failure happens on
> > AscInitAsc1000Driver step: it was freeing items of wrong struct in the
> > dvc_var union of struct asc_board, which could lead to an oops in the
> > case we set some of the fields in struct of narrow board as code was
> > choosing to always freeing wide board fields, and not everything wasn't
> > being freed/released properly.
> 
> This piece is nothing to do with a request_firmware regression, so it
> doesn't really belong here.
> 
> > Signed-off-by: Herton Ronaldo Krzesinski <herton@mandriva.com.br>
> > ---
> >  drivers/scsi/advansys.c |   35 ++++++++++++++++++++++++++---------
> >  1 files changed, 26 insertions(+), 9 deletions(-)
> > 
> > v2 fixes error handling in advansys_board_found, so code will not oops anymore
> > if firmware files are not found. users tested this change and reported it to be
> > ok (no more freeze or oops when firmware files are not found)
> > 
> > diff --git a/drivers/scsi/advansys.c b/drivers/scsi/advansys.c
> > index 22626ab..9a3c68f 100644
> > --- a/drivers/scsi/advansys.c
> > +++ b/drivers/scsi/advansys.c
> > @@ -4781,12 +4781,14 @@ static ushort AscInitAsc1000Driver(ASC_DVC_VAR *asc_dvc)
> >  	if (err) {
> >  		printk(KERN_ERR "Failed to load image \"%s\" err %d\n",
> >  		       fwname, err);
> > +		asc_dvc->err_code |= ASC_IERR_MCODE_CHKSUM;
> >  		return err;
> >  	}
> >  	if (fw->size < 4) {
> >  		printk(KERN_ERR "Bogus length %zu in image \"%s\"\n",
> >  		       fw->size, fwname);
> >  		release_firmware(fw);
> > +		asc_dvc->err_code |= ASC_IERR_MCODE_CHKSUM;
> >  		return -EINVAL;
> >  	}
> >  	chksum = (fw->data[3] << 24) | (fw->data[2] << 16) |
> > @@ -5110,12 +5112,14 @@ static int AdvInitAsc3550Driver(ADV_DVC_VAR *asc_dvc)
> >  	if (err) {
> >  		printk(KERN_ERR "Failed to load image \"%s\" err %d\n",
> >  		       fwname, err);
> > +		asc_dvc->err_code = ASC_IERR_MCODE_CHKSUM;
> >  		return err;
> >  	}
> >  	if (fw->size < 4) {
> >  		printk(KERN_ERR "Bogus length %zu in image \"%s\"\n",
> >  		       fw->size, fwname);
> >  		release_firmware(fw);
> > +		asc_dvc->err_code = ASC_IERR_MCODE_CHKSUM;
> >  		return -EINVAL;
> >  	}
> >  	chksum = (fw->data[3] << 24) | (fw->data[2] << 16) |
> > @@ -5624,12 +5628,14 @@ static int AdvInitAsc38C0800Driver(ADV_DVC_VAR *asc_dvc)
> >  	if (err) {
> >  		printk(KERN_ERR "Failed to load image \"%s\" err %d\n",
> >  		       fwname, err);
> > +		asc_dvc->err_code = ASC_IERR_MCODE_CHKSUM;
> >  		return err;
> >  	}
> >  	if (fw->size < 4) {
> >  		printk(KERN_ERR "Bogus length %zu in image \"%s\"\n",
> >  		       fw->size, fwname);
> >  		release_firmware(fw);
> > +		asc_dvc->err_code = ASC_IERR_MCODE_CHKSUM;
> >  		return -EINVAL;
> >  	}
> >  	chksum = (fw->data[3] << 24) | (fw->data[2] << 16) |
> > @@ -6124,12 +6130,14 @@ static int AdvInitAsc38C1600Driver(ADV_DVC_VAR *asc_dvc)
> >  	if (err) {
> >  		printk(KERN_ERR "Failed to load image \"%s\" err %d\n",
> >  		       fwname, err);
> > +		asc_dvc->err_code = ASC_IERR_MCODE_CHKSUM;
> >  		return err;
> >  	}
> >  	if (fw->size < 4) {
> >  		printk(KERN_ERR "Bogus length %zu in image \"%s\"\n",
> >  		       fw->size, fwname);
> >  		release_firmware(fw);
> > +		asc_dvc->err_code = ASC_IERR_MCODE_CHKSUM;
> >  		return -EINVAL;
> >  	}
> >  	chksum = (fw->data[3] << 24) | (fw->data[2] << 16) |
> > @@ -12303,7 +12311,7 @@ static int __devinit advansys_board_found(struct Scsi_Host *shost,
> >  		asc_dvc_varp->overrun_buf = kzalloc(ASC_OVERRUN_BSIZE, GFP_KERNEL);
> >  		if (!asc_dvc_varp->overrun_buf) {
> >  			ret = -ENOMEM;
> > -			goto err_free_wide_mem;
> > +			goto err_free_irq;
> >  		}
> >  		warn_code = AscInitAsc1000Driver(asc_dvc_varp);
> >  
> > @@ -12314,28 +12322,37 @@ static int __devinit advansys_board_found(struct Scsi_Host *shost,
> >  					asc_dvc_varp->err_code);
> >  			if (asc_dvc_varp->err_code) {
> >  				ret = -ENODEV;
> > -				kfree(asc_dvc_varp->overrun_buf);
> > +				goto err_free_mem;
> >  			}
> >  		}
> >  	} else {
> > -		if (advansys_wide_init_chip(shost))
> > +		if (advansys_wide_init_chip(shost)) {
> >  			ret = -ENODEV;
> > +			goto err_free_mem;
> > +		}
> >  	}
> >  
> > -	if (ret)
> > -		goto err_free_wide_mem;
> > -
> >  	ASC_DBG_PRT_SCSI_HOST(2, shost);
> >  
> >  	ret = scsi_add_host(shost, boardp->dev);
> >  	if (ret)
> > -		goto err_free_wide_mem;
> > +		goto err_free_mem;
> >  
> >  	scsi_scan_host(shost);
> >  	return 0;
> >  
> > - err_free_wide_mem:
> > -	advansys_wide_free_mem(boardp);
> > + err_free_mem:
> > +	if (ASC_NARROW_BOARD(boardp)) {
> > +		if ((asc_dvc_varp->err_code & ASC_IERR_SET_PC_ADDR) ||
> > +		    (asc_dvc_varp->err_code & ASC_IERR_START_STOP_CHIP) ||
> > +		    (!asc_dvc_varp->err_code))
> > +			dma_unmap_single(boardp->dev, asc_dvc_varp->overrun_dma,
> > +					 ASC_OVERRUN_BSIZE, DMA_FROM_DEVICE);
> 
> This is both nasty and not really a fix:  the overrun buf is still
> mapped many times on the reset path and only ever unmapped once, which
> is still an unfixed bug in this code.  I think the map needs to be moved
> out of AscInitMicroCodeVar() to somewhere in here.

I didn't want to do this since I think there will be much changes and I can't
test properly as I don't have the hardware (also may be too much for what
looks like a legacy driver/hardware). But I aggree this if is ugly and not
unmapping when needed on reset. What I thought can be better is this, to fix
error handling also on AscInitMicroCodeVar then:

diff --git a/drivers/scsi/advansys.c b/drivers/scsi/advansys.c
index 9201afe..01481d1 100644
--- a/drivers/scsi/advansys.c
+++ b/drivers/scsi/advansys.c
@@ -460,6 +460,7 @@ typedef struct asc_risc_sg_list_q {
 #define ASC_IERR_BIST_PRE_TEST		0x0800	/* BIST pre-test error */
 #define ASC_IERR_BIST_RAM_TEST		0x1000	/* BIST RAM test error */
 #define ASC_IERR_BAD_CHIPTYPE		0x2000	/* Invalid chip_type setting */
+#define ASC_IERR_DMA_MAP_SINGLE 	0x4000  /* Error with dma_map_single */
 
 #define ASC_DEF_MAX_TOTAL_QNG   (0xF0)
 #define ASC_MIN_TAG_Q_PER_DVC   (0x04)
@@ -4701,14 +4702,12 @@ static void AscInitQLinkVar(ASC_DVC_VAR *asc_dvc)
 static ushort AscInitMicroCodeVar(ASC_DVC_VAR *asc_dvc)
 {
 	int i;
-	ushort warn_code;
 	PortAddr iop_base;
 	ASC_PADDR phy_addr;
 	ASC_DCNT phy_size;
 	struct asc_board *board = asc_dvc_to_board(asc_dvc);
 
 	iop_base = asc_dvc->iop_base;
-	warn_code = 0;
 	for (i = 0; i <= ASC_MAX_TID; i++) {
 		AscPutMCodeInitSDTRAtID(iop_base, i,
 					asc_dvc->cfg->sdtr_period_offset[i]);
@@ -4724,6 +4723,10 @@ static ushort AscInitMicroCodeVar(ASC_DVC_VAR *asc_dvc)
 	BUG_ON((unsigned long)asc_dvc->overrun_buf & 7);
 	asc_dvc->overrun_dma = dma_map_single(board->dev, asc_dvc->overrun_buf,
 					ASC_OVERRUN_BSIZE, DMA_FROM_DEVICE);
+	if (dma_mapping_error(boad->dev, asc_dvc->overrun_dma)) {
+		asc_dvc->err_code |= ASC_IERR_DMA_MAP_SINGLE;
+		return -ENOMEM;
+	}
 	phy_addr = cpu_to_le32(asc_dvc->overrun_dma);
 	AscMemDWordCopyPtrToLram(iop_base, ASCV_OVERRUN_PADDR_D,
 				 (uchar *)&phy_addr, 1);
@@ -4739,14 +4742,19 @@ static ushort AscInitMicroCodeVar(ASC_DVC_VAR *asc_dvc)
 	AscSetPCAddr(iop_base, ASC_MCODE_START_ADDR);
 	if (AscGetPCAddr(iop_base) != ASC_MCODE_START_ADDR) {
 		asc_dvc->err_code |= ASC_IERR_SET_PC_ADDR;
-		return warn_code;
+		goto err_mcode_start;
 	}
 	if (AscStartChip(iop_base) != 1) {
 		asc_dvc->err_code |= ASC_IERR_START_STOP_CHIP;
-		return warn_code;
+		goto err_mcode_start;
 	}
 
-	return warn_code;
+	return 0;
+
+err_mcode_start:
+	dma_unmap_single(board->dev, asc_dvc->overrun_buf,
+			 ASC_OVERRUN_BSIZE, DMA_FROM_DEVICE);
+	return UW_ERR;
 }
 
 static ushort AscInitAsc1000Driver(ASC_DVC_VAR *asc_dvc)
@@ -4802,6 +4810,8 @@ static ushort AscInitAsc1000Driver(ASC_DVC_VAR *asc_dvc)
 	}
 	release_firmware(fw);
 	warn_code |= AscInitMicroCodeVar(asc_dvc);
+	if (asc_dvc->err_code != 0)
+		return warn_code;
 	asc_dvc->init_state |= ASC_INIT_STATE_END_LOAD_MC;
 	AscEnableInterrupt(iop_base);
 	return warn_code;
@@ -12311,7 +12321,7 @@ static int __devinit advansys_board_found(struct Scsi_Host *shost,
 		asc_dvc_varp->overrun_buf = kzalloc(ASC_OVERRUN_BSIZE, GFP_KERNEL);
 		if (!asc_dvc_varp->overrun_buf) {
 			ret = -ENOMEM;
-			goto err_free_wide_mem;
+			goto err_free_irq;
 		}
 		warn_code = AscInitAsc1000Driver(asc_dvc_varp);
 
@@ -12322,28 +12332,31 @@ static int __devinit advansys_board_found(struct Scsi_Host *shost,
 					asc_dvc_varp->err_code);
 			if (asc_dvc_varp->err_code) {
 				ret = -ENODEV;
-				kfree(asc_dvc_varp->overrun_buf);
+				goto err_free_mem;
 			}
 		}
 	} else {
-		if (advansys_wide_init_chip(shost))
+		if (advansys_wide_init_chip(shost)) {
 			ret = -ENODEV;
+			goto err_free_mem;
+		}
 	}
 
-	if (ret)
-		goto err_free_wide_mem;
-
 	ASC_DBG_PRT_SCSI_HOST(2, shost);
 
 	ret = scsi_add_host(shost, boardp->dev);
 	if (ret)
-		goto err_free_wide_mem;
+		goto err_free_mem;
 
 	scsi_scan_host(shost);
 	return 0;
 
- err_free_wide_mem:
-	advansys_wide_free_mem(boardp);
+ err_free_mem:
+	if (ASC_NARROW_BOARD(boardp))
+		kfree(asc_dvc_varp->overrun_buf);
+	else
+		advansys_wide_free_mem(boardp);
+ err_free_irq:
 	free_irq(boardp->irq, shost);
  err_free_dma:
 #ifdef CONFIG_ISA


To me looks safer than moving everything out from AscInitMicroCodeVar,
what do you think? If it's ok I submit it with changelog/signed-off

> 
> James
> 
> > +		kfree(asc_dvc_varp->overrun_buf);
> > +	} else {
> > +		advansys_wide_free_mem(boardp);
> > +	}
> > + err_free_irq:
> >  	free_irq(boardp->irq, shost);
> >   err_free_dma:
> >  #ifdef CONFIG_ISA

-- 
[]'s
Herton
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