From aecbafc041502925052bd47133606f46f2ee8984 Mon Sep 17 00:00:00 2001 From: Finn Thain Date: Tue, 16 Oct 2018 16:31:25 +1100 Subject: [PATCH] scsi: esp_scsi: Track residual for PIO transfers commit fd47d919d0c336e7c22862b51ee94927ffea227a upstream. If a target disconnects during a PIO data transfer the command may fail when the target reconnects: scsi host1: DMA length is zero! scsi host1: cur adr[04380000] len[00000000] The scsi bus is then reset. This happens because the residual reached zero before the transfer was completed. The usual residual calculation relies on the Transfer Count registers. That works for DMA transfers but not for PIO transfers. Fix the problem by storing the PIO transfer residual and using that to correctly calculate bytes_sent. Fixes: 6fe07aaffbf0 ("[SCSI] m68k: new mac_esp scsi driver") Tested-by: Stan Johnson Signed-off-by: Finn Thain Tested-by: Michael Schmitz Signed-off-by: Martin K. Petersen Signed-off-by: Ben Hutchings --- drivers/scsi/esp_scsi.c | 1 + drivers/scsi/esp_scsi.h | 2 ++ drivers/scsi/mac_esp.c | 2 ++ 3 files changed, 5 insertions(+) diff --git a/drivers/scsi/esp_scsi.c b/drivers/scsi/esp_scsi.c index 55548dc5cec3..cc674370b4b0 100644 --- a/drivers/scsi/esp_scsi.c +++ b/drivers/scsi/esp_scsi.c @@ -1316,6 +1316,7 @@ static int esp_data_bytes_sent(struct esp *esp, struct esp_cmd_entry *ent, bytes_sent = esp->data_dma_len; bytes_sent -= ecount; + bytes_sent -= esp->send_cmd_residual; if (!(ent->flags & ESP_CMD_FLAG_WRITE)) bytes_sent -= fifo_cnt; diff --git a/drivers/scsi/esp_scsi.h b/drivers/scsi/esp_scsi.h index cd68805e8d78..20b229b53639 100644 --- a/drivers/scsi/esp_scsi.h +++ b/drivers/scsi/esp_scsi.h @@ -524,6 +524,8 @@ struct esp { void *dma; int dmarev; + + u32 send_cmd_residual; }; /* A front-end driver for the ESP chip should do the following in diff --git a/drivers/scsi/mac_esp.c b/drivers/scsi/mac_esp.c index c1497fddf0b4..364eb9969e8c 100644 --- a/drivers/scsi/mac_esp.c +++ b/drivers/scsi/mac_esp.c @@ -426,6 +426,8 @@ static void mac_esp_send_pio_cmd(struct esp *esp, u32 addr, u32 esp_count, scsi_esp_cmd(esp, ESP_CMD_TI); } } + + esp->send_cmd_residual = esp_count; } static int mac_esp_irq_pending(struct esp *esp)