libata: update atapi_eh_request_sense() such that lbam/lbah contains buffer size

With ATAPI transfer chunk size properly programmed, libata PIO HSM should be able to handle full spurious data chunks. Also, it's a good idea to suppress trailing data warning for misc ATAPI commands as there can be many of them per command - for example, if the chunk size is 16 and the drive tries to transfer 510 bytes, there can be 31 trailing data messages.

This patch makes the following updates to libata ATAPI PIO HSM implementation.

* Make it drain full spurious chunks.

* Suppress trailing data warning message for misc commands.

* Put limit on how many bytes can be drained.

* If odd, round up consumed bytes and the number of bytes to be drained. This gets the number of bytes to drain right for drivers which do 16bit PIO.

This patch is partial backport of improve-ATAPI-data-xfer patchset pending for #upstream.

Signed-off-by Tejun Heo <[email protected]>

---
This combined with the previous patch fixes bug 9346.

 drivers/ata/libata-core.c |   87 ++++++++++++++++++++++++++++++++++------------
 include/linux/libata.h    |    2 +
 2 files changed, 67 insertions(+), 22 deletions(-)

Index: work/drivers/ata/libata-core.c
===================================================================

drivers/ata/libata-core.c +25 -0

@@ -64,6 +64,7 @@
 #include <linux/libata.h>
 #include <asm/semaphore.h>
 #include <asm/byteorder.h>
+#include <linux/cdrom.h>
 
 #include "libata.h"
 

@@ -4649,6 +4650,43 @@ int ata_check_atapi_dma(struct ata_queue
 }
 
 /**
+ *	atapi_qc_may_overflow - Check whether data transfer may overflow
+ *	@qc: ATA command in question
+ *
+ *	ATAPI commands which transfer variable length data to host
+ *	might overflow due to application error or hardare bug.  This
+ *	function checks whether overflow should be drained and ignored
+ *	for @qc.
+ *
+ *	LOCKING:
+ *	None.
+ *
+ *	RETURNS:
+ *	1 if @qc may overflow; otherwise, 0.
+ */
+static int atapi_qc_may_overflow(struct ata_queued_cmd *qc)
+{
+	if (qc->tf.protocol != ATA_PROT_ATAPI &&
+	    qc->tf.protocol != ATA_PROT_ATAPI_DMA)
+		return 0;
+
+	if (qc->tf.flags & ATA_TFLAG_WRITE)
+		return 0;
+
+	switch (qc->cdb[0]) {

While updating lbam/h for ATAPI commands, atapi_eh_request_sense() was left out. Update it.

Signed-off-by Tejun Heo <[email protected]>

---
This patch is from improve-ATAPI-data-xfer patchset pending for #upstream.

 drivers/ata/libata-eh.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Index: work/drivers/ata/libata-eh.c
===================================================================

drivers/ata/libata-eh.c +2 -2

@@ -1264,8 +1264,8 @@ static unsigned int atapi_eh_request_sen
 		tf.feature |= ATAPI_PKT_DMA;
 	} else {
 		tf.protocol = ATA_PROT_ATAPI;
-		tf.lbam = (8 * 1024) & 0xff;
-		tf.lbah = (8 * 1024) >> 8;
+		tf.lbam = SCSI_SENSE_BUFFERSIZE;
+		tf.lbah = 0;
 	}
 
 	return ata_exec_internal(dev, &tf, cdb, DMA_FROM_DEVICE,

Hello guys,

Yannick does it work ok for you when you try to blank a dvd+rw disc ? Mine no longer jams up the drive now but it does say that the media or drive does not support blanking. I'm thinking its either because these discs just do multisession so this is what was meant to happen all along or there's still something going on.

This drive or media does not support the 'BLANK media' command
wodim: Cannot blank disk, aborting.
wodim: Some drives do not support all blank types.
wodim: Try again with wodim blank=all.

Quoted 7 lines

Hello guys,

Yannick does it work ok for you when you try to blank a dvd+rw disc ? Mine no longer jams up the drive now but it does say that the media or drive does not support blanking. I'm thinking its either because these discs just do multisession so this is what was meant to happen all along or there's still something going on.

Does the kernel complain about anything?

This drive or media does not support the 'BLANK media' command

Quoted 3 lines

wodim: Cannot blank disk, aborting.
wodim: Some drives do not support all blank types.
wodim: Try again with wodim blank=all.

wodim suggests "blank=all", does it work?

Quoted 6 lines

This drive or media does not support the 'BLANK media' command

Quoted 3 lines

wodim: Cannot blank disk, aborting.
wodim: Some drives do not support all blank types.
wodim: Try again with wodim blank=all.

wodim suggests "blank=all", does it work?

Nope same thing happens.

"dvd+rw-format /dev/sr0 -force" Works ok though.

Hello,

Quoted 9 lines · Will Trives

Quoted 6 lines

This drive or media does not support the 'BLANK media' command

Quoted 3 lines

wodim: Cannot blank disk, aborting.
wodim: Some drives do not support all blank types.
wodim: Try again with wodim blank=all.

wodim suggests "blank=all", does it work?

Nope same thing happens.

"dvd+rw-format /dev/sr0 -force" Works ok though.

This looks like a wodim or drive/media problem and for some reason wodim thinks that the media can't be blanked. Hmmm.. why do you need -force to dvd+rw-format? What happens if you don't use -force?

Hello guys,

Yannick does it work ok for you when you try to blank a dvd+rw disc ? Mine no longer jams up the drive now but it does say that the media or drive does not support blanking.

While updating lbam/h for ATAPI commands, atapi_eh_request_sense() was left out. Update it.

Signed-off-by Tejun Heo <[email protected]>

---
This patch is from improve-ATAPI-data-xfer patchset pending for #upstream.

 drivers/ata/libata-eh.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)