[PATCH] scsi: sd: Use warn for logs about no caching info

[PATCH] scsi: sd: Use warn for logs about no caching info

[Jeremy Cline]

When no caching mode information can be found for a disk, use the
warning log level rather than error. It is common for this to occur
with cheap USB sticks.

Signed-off-by: Jeremy Cline <jeremy@jcline.org>
---
 drivers/scsi/sd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index a028ab3322a9..9838d94b047e 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2789,7 +2789,7 @@ sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
 			}
 		}
 
-		sd_first_printk(KERN_ERR, sdkp, "No Caching mode page found\n");
+		sd_first_printk(KERN_WARNING, sdkp, "No Caching mode page found\n");
 		goto defaults;
 
 	Page_found:
@@ -2844,7 +2844,7 @@ sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
 				"Assuming drive cache: write back\n");
 		sdkp->WCE = 1;
 	} else {
-		sd_first_printk(KERN_ERR, sdkp,
+		sd_first_printk(KERN_WARNING, sdkp,
 				"Assuming drive cache: write through\n");
 		sdkp->WCE = 0;
 	}
-- 
2.14.3

Re: [PATCH] scsi: sd: Use warn for logs about no caching info

[Martin K. Petersen]

Hi Jeremy,

> When no caching mode information can be found for a disk, use the
> warning log level rather than error. It is common for this to occur
> with cheap USB sticks.

Just because something is common occurrence doesn't mean it's not an
error. What's the rationale behind demoting this to a warning?

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH] scsi: sd: Use warn for logs about no caching info

[Jeremy Cline]

On Wed, Jan 03, 2018 at 10:50:29PM -0500, Martin K. Petersen wrote:
> 
> Hi Jeremy,
> 
> > When no caching mode information can be found for a disk, use the
> > warning log level rather than error. It is common for this to occur
> > with cheap USB sticks.
> 
> Just because something is common occurrence doesn't mean it's not an
> error. What's the rationale behind demoting this to a warning?

That's true, that's not a particularly compelling reason. My rationale
is that in this case when it can't find the cache info it drops back to
sane defaults and works fine. It's certainly something to note, but
I wouldn't describe it as an "error condition".

Regards,
Jeremy