From: Paolo Bonzini <pbonzini@redhat.com>

Date: Wed, 15 Jun 2016 14:29:33 +0200

Subject: [PATCH] scsi: esp: clean up handle_ti/esp_do_dma if s->do_cmd

Avoid duplicated code between esp_do_dma and handle_ti.  esp_do_dma

has the same code that handle_ti contains after the call to esp_do_dma;

but the code in handle_ti is never reached because it is in an "else if".

Remove the else and also the pointless return.

esp_do_dma also has a partially dead assignment of the to_device

variable.  Sink it to the point where it's actually used.

Finally, assert that the other caller of esp_do_dma (esp_transfer_data)

only transfers data and not a command.  This is true because get_cmd

cancels the old request synchronously before its caller handle_satn_stop

sets do_cmd to 1.

Reviewed-by: Laszlo Ersek <lersek@redhat.com>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

(cherry picked from commit 7f0b6e114ae4e142e2b3dfc9fac138f4a30edc4f)

---

 hw/scsi/esp.c | 11 ++++-------

 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c

index 6407844..68d3e4d 100644

--- a/hw/scsi/esp.c

+++ b/hw/scsi/esp.c

@@ -245,15 +245,10 @@ static void esp_do_dma(ESPState *s)

     uint32_t len;

     int to_device;

-    to_device = (s->ti_size < 0);

     len = s->dma_left;

     if (s->do_cmd) {

         trace_esp_do_dma(s->cmdlen, len);

         s->dma_memory_read(s->dma_opaque, &s->cmdbuf[s->cmdlen], len);

-        s->ti_size = 0;

-        s->cmdlen = 0;

-        s->do_cmd = 0;

-        do_cmd(s, s->cmdbuf);

         return;

     }

     if (s->async_len == 0) {

@@ -263,6 +258,7 @@ static void esp_do_dma(ESPState *s)

     if (len > s->async_len) {

         len = s->async_len;

     }

+    to_device = (s->ti_size < 0);

     if (to_device) {

         s->dma_memory_read(s->dma_opaque, s->async_buf, len);

     } else {

@@ -318,6 +314,7 @@ void esp_transfer_data(SCSIRequest *req, uint32_t len)

 {

     ESPState *s = req->hba_private;

+    assert(!s->do_cmd);

     trace_esp_transfer_data(s->dma_left, s->ti_size);

     s->async_len = len;

     s->async_buf = scsi_req_get_buf(req);

@@ -358,13 +355,13 @@ static void handle_ti(ESPState *s)

         s->dma_left = minlen;

         s->rregs[ESP_RSTAT] &= ~STAT_TC;

         esp_do_dma(s);

-    } else if (s->do_cmd) {

+    }

+    if (s->do_cmd) {

         trace_esp_handle_ti_cmd(s->cmdlen);

         s->ti_size = 0;

         s->cmdlen = 0;

         s->do_cmd = 0;

         do_cmd(s, s->cmdbuf);

-        return;

     }

 }