linux-toradex.git/drivers/scsi/esp_scsi.c, branch v4.19-rc4

scsi: esp_scsi: Always clear msg_out_len after MESSAGE OUT phase

2017-08-10T23:55:35+00:00

After sending a message, always clear esp->msg_out_len. Otherwise,
eh_abort_handler may subsequently fail to send an ABORT TASK SET
message.

Tested-by: Stan Johnson 
Signed-off-by: Finn Thain 
Signed-off-by: Martin K. Petersen

scsi: esp_scsi: Avoid sending ABORT TASK SET messages

2017-08-10T23:55:35+00:00

If an LLD aborts a task set, it should complete the affected commands
with the appropriate result code. In a couple of cases esp_scsi doesn't
do so.

When the initiator receives an unhandled message, just respond by sending
a MESSAGE REJECT instead of ABORT TASK SET, and thus avoid the issue.

OTOH, a MESSAGE REJECT sent by a target can be taken as an indication
that the initiator messed up somehow. It isn't always possible to abort
correctly, so just fall back on a SCSI bus reset, which will complete the
affected commands with the appropriate result code.

For example, certain Apple (Sony) CD-ROM drives, when the non-existent
LUN 1 is scanned, can't handle the INQUIRY command. The problem is not
detected until the initiator gets a MESSAGE REJECT. Whenever esp_scsi
sees that message, it raises ATN and sends ABORT TASK SET -- but
neglects to complete the failed scmd.

The target then goes into DATA OUT phase (probably bogus), while the ESP
device goes into disconnected mode (surprising, given the bus phase).
The next Transfer Information command from esp_scsi then causes
an Invalid Command interrupt because that command is not valid when in
disconnected mode:

mac_esp: using PDMA for controller 0
mac_esp mac_esp.0: esp0: regs[50f10000:(null)] irq[19]
mac_esp mac_esp.0: esp0: is a ESP236, 16 MHz (ccf=4), SCSI ID 7
scsi host0: esp
scsi 0:0:0:0: Direct-Access     SEAGATE  ST318416N        0010 PQ: 0 ANSI: 3
scsi target0:0:0: Beginning Domain Validation
scsi target0:0:0: asynchronous
scsi target0:0:0: Domain Validation skipping write tests
scsi target0:0:0: Ending Domain Validation
scsi 0:0:3:0: CD-ROM            SONY     CD-ROM CDU-8003A 1.9a PQ: 0 ANSI: 2 CCS
scsi target0:0:3: Beginning Domain Validation
scsi target0:0:3: FAST-5 SCSI 2.0 MB/s ST (500 ns, offset 15)
scsi target0:0:3: Domain Validation skipping write tests
scsi target0:0:3: Ending Domain Validation
scsi host0: unexpected IREG 40
scsi host0: Dumping command log
scsi host0: ent[2] CMD val[c2] sreg[90] seqreg[cc] sreg2[00] ireg[20] ss[01] event[0c]
scsi host0: ent[3] CMD val[00] sreg[91] seqreg[04] sreg2[00] ireg[18] ss[00] event[0c]
scsi host0: ent[4] EVENT val[0d] sreg[91] seqreg[04] sreg2[00] ireg[18] ss[00] event[0c]
scsi host0: ent[5] EVENT val[03] sreg[91] seqreg[04] sreg2[00] ireg[18] ss[00] event[0d]
scsi host0: ent[6] CMD val[90] sreg[91] seqreg[04] sreg2[00] ireg[18] ss[00] event[03]
scsi host0: ent[7] EVENT val[05] sreg[91] seqreg[04] sreg2[00] ireg[18] ss[00] event[03]
scsi host0: ent[8] EVENT val[0d] sreg[93] seqreg[cc] sreg2[00] ireg[10] ss[00] event[05]
scsi host0: ent[9] CMD val[01] sreg[93] seqreg[cc] sreg2[00] ireg[10] ss[00] event[0d]
scsi host0: ent[10] CMD val[11] sreg[93] seqreg[cc] sreg2[00] ireg[10] ss[00] event[0d]
scsi host0: ent[11] EVENT val[0b] sreg[93] seqreg[cc] sreg2[00] ireg[10] ss[00] event[0d]
scsi host0: ent[12] CMD val[12] sreg[97] seqreg[cc] sreg2[00] ireg[08] ss[00] event[0b]
scsi host0: ent[13] EVENT val[0c] sreg[97] seqreg[cc] sreg2[00] ireg[08] ss[00] event[0b]
scsi host0: ent[14] CMD val[44] sreg[90] seqreg[cc] sreg2[00] ireg[20] ss[00] event[0c]
scsi host0: ent[15] CMD val[01] sreg[90] seqreg[cc] sreg2[00] ireg[20] ss[01] event[0c]
scsi host0: ent[16] CMD val[c2] sreg[90] seqreg[cc] sreg2[00] ireg[20] ss[01] event[0c]
scsi host0: ent[17] CMD val[00] sreg[87] seqreg[02] sreg2[00] ireg[18] ss[00] event[0c]
scsi host0: ent[18] EVENT val[0d] sreg[87] seqreg[02] sreg2[00] ireg[18] ss[00] event[0c]
scsi host0: ent[19] EVENT val[06] sreg[87] seqreg[02] sreg2[00] ireg[18] ss[00] event[0d]
scsi host0: ent[20] CMD val[01] sreg[87] seqreg[02] sreg2[00] ireg[18] ss[00] event[06]
scsi host0: ent[21] CMD val[10] sreg[87] seqreg[02] sreg2[00] ireg[18] ss[00] event[06]
scsi host0: ent[22] CMD val[1a] sreg[87] seqreg[ca] sreg2[00] ireg[08] ss[00] event[06]
scsi host0: ent[23] CMD val[12] sreg[87] seqreg[ca] sreg2[00] ireg[08] ss[00] event[06]
scsi host0: ent[24] EVENT val[0d] sreg[87] seqreg[ca] sreg2[00] ireg[08] ss[00] event[06]
scsi host0: ent[25] EVENT val[09] sreg[86] seqreg[ca] sreg2[00] ireg[10] ss[00] event[0d]
scsi host0: ent[26] CMD val[01] sreg[86] seqreg[ca] sreg2[00] ireg[10] ss[00] event[09]
scsi host0: ent[27] CMD val[10] sreg[86] seqreg[ca] sreg2[00] ireg[10] ss[00] event[09]
scsi host0: ent[28] EVENT val[0a] sreg[86] seqreg[ca] sreg2[00] ireg[10] ss[00] event[09]
scsi host0: ent[29] EVENT val[0d] sreg[80] seqreg[ca] sreg2[00] ireg[20] ss[00] event[0a]
scsi host0: ent[30] EVENT val[04] sreg[80] seqreg[ca] sreg2[00] ireg[20] ss[00] event[0d]
scsi host0: ent[31] CMD val[01] sreg[80] seqreg[ca] sreg2[00] ireg[20] ss[00] event[04]
scsi host0: ent[0] CMD val[90] sreg[80] seqreg[ca] sreg2[00] ireg[20] ss[00] event[04]
scsi host0: ent[1] EVENT val[05] sreg[80] seqreg[ca] sreg2[00] ireg[20] ss[00] event[04]
scsi target0:0:3: FAST-5 SCSI 2.0 MB/s ST (500 ns, offset 15)
scsi target0:0:0: asynchronous
sr 0:0:3:0: [sr0] scsi-1 drive
cdrom: Uniform CD-ROM driver Revision: 3.20
sd 0:0:0:0: Attached scsi generic sg0 type 0
sr 0:0:3:0: Attached scsi generic sg1 type 5

This patch resolves this issue because the bus reset causes the INQUIRY
command to fail earlier, and return the appropriate result code.

Tested-by: Stan Johnson 
Signed-off-by: Finn Thain 
Signed-off-by: Martin K. Petersen

scsi: esp_scsi: Clean up control flow and dead code

2017-08-10T23:55:34+00:00

This patch improves readability. There are no functional changes.

Since this touches on a questionable ESP_INTR_DC conditional, add some
commentary to help others who may (as I did) find themselves chasing an
"Invalid Command" error after the device flags this condition.

This cleanup also eliminates a warning from "make W=1":
drivers/scsi/esp_scsi.c: In function 'esp_finish_select':
drivers/scsi/esp_scsi.c:1233:5: warning: variable 'orig_select_state' set but not used [-Wunused-but-set-variable]
  u8 orig_select_state;

Tested-by: Stan Johnson 
Signed-off-by: Finn Thain 
Signed-off-by: Martin K. Petersen

scsi: use host wide tags by default

2015-11-10T01:11:57+00:00

This patch changes the !blk-mq path to the same defaults as the blk-mq
I/O path by always enabling block tagging, and always using host wide
tags.  We've had blk-mq available for a few releases so bugs with
this mode should have been ironed out, and this ensures we get better
coverage of over tagging setup over different configs.

Signed-off-by: Christoph Hellwig 
Acked-by: Jens Axboe 
Reviewed-by: Hannes Reinecke 
Signed-off-by: James Bottomley

esp_scsi: remove check for ESP_MAX_TAGS

2015-01-09T14:44:23+00:00

'num_tags' is an unsigned char, so the check for 'ESP_MAX_TAGS'
(which is set to 256) is pointless.

Acked-by: Geert Uytterhoeven 
Signed-off-by: Hannes Reinecke 
Signed-off-by: Christoph Hellwig

esp_scsi: enable CONFIG2_FENAB for am53c974

2014-11-24T15:13:17+00:00

CONFIG2_FENAB ('feature enable') changed definition between chip
revisions, from 'Latch SCSI Phase' to 'Latch SCSI Phase, display
chip ID upon reset, and enable 24 bit addresses'.
So only enable it for am53c974 where we know what it's doing.

Acked-by: David S. Miller 
Reviewed-by: Paolo Bonzini 
Signed-off-by: Hannes Reinecke 
Signed-off-by: Christoph Hellwig

esp_scsi: let DMA driver provide a config2 value

2014-11-24T15:13:17+00:00

On PCscsi, the FENAB configuration also enables 24-bit DMA
transfer lengths (and provides the chip id in TCHI after reset).
We want to be able to enable this parameter from the DMA driver.

Check if the caller of scsi_esp_register provided a value for esp->config2.
If this is the case, assume this is not an ESP100, skip the detection
phase and leave esp->config2 untouched.  It will be used in esp_reset_esp.

Reviewed-by: Hannes Reinecke 
Acked-by: David S. Miller 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Christoph Hellwig

esp_scsi: correctly detect am53c974

2014-11-24T15:13:16+00:00

The am53c974 returns the same ID as the FAS236, but implements
things slightly differently. So detect the am53c974 by checking
for ESP_CONFIG4 register.

Reviewed-by: Paolo Bonzini 
Signed-off-by: Hannes Reinecke 
Signed-off-by: Christoph Hellwig

am53c974: BLAST residual handling

2014-11-24T15:13:15+00:00

The am53c974 has an design issue where a single byte might be
left in the SCSI FIFO after a DMA transfer.
As the handling code is currently untested add a WARN_ON()
statement here.

Reviewed-by: Paolo Bonzini 
Acked-by: David S. Miller 
Signed-off-by: Hannes Reinecke 
Signed-off-by: Christoph Hellwig

esp_scsi: use FIFO for command submission

2014-11-24T15:10:24+00:00

Using DMA for command submission has the drawback that it might
generate additional DMA completion interrupts after the command
has been submitted to the device.
Additionally the am53c974 has a design flaw causing it
to generate spurious interrupts even though DMA completion
interrupts are not enabled.
This can be avoided by using the FIFO for command submission.

Reviewed-by: Paolo Bonzini 
Acked-by: David S. Miller 
Signed-off-by: Hannes Reinecke 
Signed-off-by: Christoph Hellwig