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authorHannes Reinecke <hare@suse.de>2014-11-24 15:37:26 +0100
committerChristoph Hellwig <hch@lst.de>2014-11-24 16:13:15 +0100
commit6df388f2d549d3a2a7ad58b632d2ecd25fc0ff3f (patch)
tree7b663c4ebd1da38079723da2989e7f44388a52f2 /drivers/scsi/am53c974.c
parent3a7e7be2a9a2105742c3c88d466ea2158a03a837 (diff)
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am53c974: BLAST residual handling
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 <pbonzini@redhat.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'drivers/scsi/am53c974.c')
-rw-r--r--drivers/scsi/am53c974.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/scsi/am53c974.c b/drivers/scsi/am53c974.c
index a16c9cf0f0a2..a42e8db057a4 100644
--- a/drivers/scsi/am53c974.c
+++ b/drivers/scsi/am53c974.c
@@ -200,6 +200,12 @@ static void pci_esp_dma_drain(struct esp *esp)
}
pci_esp_write8(esp, ESP_DMA_CMD_DIR | ESP_DMA_CMD_IDLE, ESP_DMA_CMD);
esp_dma_log("DMA blast done (%d tries, %d bytes left)\n", lim, resid);
+ /* BLAST residual handling is currently untested */
+ if (WARN_ON_ONCE(resid == 1)) {
+ struct esp_cmd_entry *ent = esp->active_cmd;
+
+ ent->flags |= ESP_CMD_FLAG_RESIDUAL;
+ }
}
static void pci_esp_dma_invalidate(struct esp *esp)