esp_scsi: correctly detect am53c974
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 <pbonzini@redhat.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/drivers/scsi/esp_scsi.c b/drivers/scsi/esp_scsi.c
index 4366011..3fb6a00 100644
--- a/drivers/scsi/esp_scsi.c
+++ b/drivers/scsi/esp_scsi.c
@@ -268,6 +268,19 @@
} else {
esp->min_period = ((5 * esp->ccycle) / 1000);
}
+ if (esp->rev == FAS236) {
+ /*
+ * The AM53c974 chip returns the same ID as FAS236;
+ * try to configure glitch eater.
+ */
+ u8 config4 = ESP_CONFIG4_GE1;
+ esp_write8(config4, ESP_CFG4);
+ config4 = esp_read8(ESP_CFG4);
+ if (config4 & ESP_CONFIG4_GE1) {
+ esp->rev = PCSCSI;
+ esp_write8(esp->config4, ESP_CFG4);
+ }
+ }
esp->max_period = (esp->max_period + 3)>>2;
esp->min_period = (esp->min_period + 3)>>2;
@@ -293,7 +306,8 @@
/* fallthrough... */
case FAS236:
- /* Fast 236 or HME */
+ case PCSCSI:
+ /* Fast 236, AM53c974 or HME */
esp_write8(esp->config2, ESP_CFG2);
if (esp->rev == FASHME) {
u8 cfg3 = esp->target[0].esp_config3;
@@ -2364,6 +2378,7 @@
"FAS100A",
"FAST",
"FASHME",
+ "AM53C974",
};
static struct scsi_transport_template *esp_transport_template;
