From: "Martin K. Petersen" martin.petersen@oracle.com
[ Upstream commit 597d74005ba85e87c256cd732128ebf7faf54247 ]
The USB storage glue sets the try_rc_10_first flag in an attempt to avoid wedging poorly implemented legacy USB devices.
If the device capacity is too large to be expressed in the provided response buffer field of READ CAPACITY(10), a well-behaved device will set the reported capacity to 0xFFFFFFFF. We will then attempt to issue a READ CAPACITY(16) to obtain the real capacity.
Since this part of the discovery logic is not covered by the first_scan flag, a warning will be printed a couple of times times per revalidate attempt if we upgrade from READ CAPACITY(10) to READ CAPACITY(16).
Remember that we have successfully issued READ CAPACITY(16) so we can take the fast path on subsequent revalidate attempts.
Reported-by: Menion menion@gmail.com Reviewed-by: Laurence Oberman loberman@redhat.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/sd.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 4a532318b211..b0dd8bdfdf98 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -2497,6 +2497,8 @@ sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer) sector_size = old_sector_size; goto got_data; } + /* Remember that READ CAPACITY(16) succeeded */ + sdp->try_rc_10_first = 0; } }