From 349cd7cfe6ba0b2e7cd2afdc3e70ede845311afe Mon Sep 17 00:00:00 2001 From: James Bottomley Date: Mon, 28 Nov 2005 15:41:58 -0600 Subject: [PATCH] [SCSI] SPI DV: be more conservative about echo buffer usage Some SCSI devices apparently get very confused if we try to use the echo buffer on a non-DT negotiated bus (this mirrors the problems of using PPR on non-LVD for some devices). The fix is to be far more conservative about when we use an echo buffer. With this patch, we'll now see what parameters are negotiated by the read only test, and only look for an echo buffer if DT is negotiated. Signed-off-by: James Bottomley --- drivers/scsi/scsi_transport_spi.c | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-) diff --git a/drivers/scsi/scsi_transport_spi.c b/drivers/scsi/scsi_transport_spi.c index 718a2bc4ed5..38a53b5f9e9 100644 --- a/drivers/scsi/scsi_transport_spi.c +++ b/drivers/scsi/scsi_transport_spi.c @@ -812,12 +812,10 @@ spi_dv_device_internal(struct scsi_device *sdev, u8 *buffer) if (!scsi_device_sync(sdev) && !scsi_device_dt(sdev)) return; - /* see if the device has an echo buffer. If it does we can - * do the SPI pattern write tests */ - - len = 0; - if (scsi_device_dt(sdev)) - len = spi_dv_device_get_echo_buffer(sdev, buffer); + /* len == -1 is the signal that we need to ascertain the + * presence of an echo buffer before trying to use it. len == + * 0 means we don't have an echo buffer */ + len = -1; retry: @@ -840,11 +838,23 @@ spi_dv_device_internal(struct scsi_device *sdev, u8 *buffer) if (spi_min_period(starget) == 8) DV_SET(pcomp_en, 1); } + /* Do the read only INQUIRY tests */ + spi_dv_retrain(sdev, buffer, buffer + sdev->inquiry_len, + spi_dv_device_compare_inquiry); + /* See if we actually managed to negotiate and sustain DT */ + if (i->f->get_dt) + i->f->get_dt(starget); + + /* see if the device has an echo buffer. If it does we can do + * the SPI pattern write tests. Because of some broken + * devices, we *only* try this on a device that has actually + * negotiated DT */ + + if (len == -1 && spi_dt(starget)) + len = spi_dv_device_get_echo_buffer(sdev, buffer); - if (len == 0) { + if (len <= 0) { starget_printk(KERN_INFO, starget, "Domain Validation skipping write tests\n"); - spi_dv_retrain(sdev, buffer, buffer + len, - spi_dv_device_compare_inquiry); return; } -- 2.41.1