[PATCH] flashrom: Handle WREN and EWSR failure gracefully on ICH/VIA SPI

[Carl-Daniel Hailfinger]

Until the ICH SPI driver can handle preopcodes as standalone opcodes, we
should handle such special opcode failure gracefully on ICH and
compatible chipsets.

This fixes status register writes on almost all ICH+VIA SPI masters.

The fix is almost identical to r484, but this time it affects the EWSR
(Enable Write Status Register) opcode instead of the WREN (Write Enable)
opcode.

With the differentiated return codes introduced in r500, the workaround
is more precise this time. The old WREN workaround was updated as well.

Signed-off-by: Carl-Daniel Hailfinger

Index: flashrom-spi_wren_ewsr_error_checking_ichspi_workaround/spi.c
===================================================================
--- flashrom-spi_wren_ewsr_error_checking_ichspi_workaround/spi.c	(Revision 505)
+++ flashrom-spi_wren_ewsr_error_checking_ichspi_workaround/spi.c	(Arbeitskopie)
@@ -116,8 +116,10 @@

/* Send WREN (Write Enable) */
    result = spi_command(sizeof(cmd), 0, cmd, NULL);
-	if (result) {
-		printf_debug("spi_write_enable failed");
+
+	if (result)
+		printf_debug("%s failed", __func__);
+	if (result == SPI_INVALID_OPCODE) {
    	switch (flashbus) {
    	case BUS_TYPE_ICH7_SPI:
    	case BUS_TYPE_ICH9_SPI:
@@ -126,9 +128,12 @@
    			     " and hoping it will be run as PREOP\n");
    		return 0;
    	default:
-			printf_debug("\n");
+			break;
    	}
    }
+	if (result)
+		printf_debug("\n");
+
    return result;
 }

@@ -555,9 +560,29 @@
 int spi_write_status_enable(void)
 {
    const unsigned char cmd[JEDEC_EWSR_OUTSIZE] = { JEDEC_EWSR };
+	int result;

/* Send EWSR (Enable Write Status Register). */
-	return spi_command(JEDEC_EWSR_OUTSIZE, JEDEC_EWSR_INSIZE, cmd, NULL);
+	result = spi_command(sizeof(cmd), JEDEC_EWSR_INSIZE, cmd, NULL);
+
+	if (result)
+		printf_debug("%s failed", __func__);
+	if (result == SPI_INVALID_OPCODE) {
+		switch (flashbus) {
+		case BUS_TYPE_ICH7_SPI:
+		case BUS_TYPE_ICH9_SPI:
+		case BUS_TYPE_VIA_SPI:
+			printf_debug(" due to SPI master limitation, ignoring"
+				     " and hoping it will be run as PREOP\n");
+			return 0;
+		default:
+			break;
+		}
+	}
+	if (result)
+		printf_debug("\n");
+
+	return result;
 }

/*

[PATCH] flashrom: Handle WREN and EWSR failure gracefully on ICH/VIA SPI

[FENG Yu Ning]

Carl-Daniel Hailfinger wrote:
> Until the ICH SPI driver can handle preopcodes as standalone opcodes, we
> should handle such special opcode failure gracefully on ICH and
> compatible chipsets.

Acked-by: FENG Yu Ning

iirc, Rudolf came to similar solution before, and I tried to hold it
back. That might be a wrong decision.

I still don't like that much. However, I realize that personal taste
is a bad reason to hold back a workaround for a long time. I don't
want to make a wrong decision once more.

It seems not many are interested in it. Here is my ack.

yu ning

[Cristi Magherusan]

On Thu, 2009-05-14 at 22:51 +0800, FENG Yu Ning wrote:
> Carl-Daniel Hailfinger wrote:
> > Until the ICH SPI driver can handle preopcodes as standalone opcodes, we
> > should handle such special opcode failure gracefully on ICH and
> > compatible chipsets.
>
> Acked-by: FENG Yu Ning
>
> iirc, Rudolf came to similar solution before, and I tried to hold it
> back. That might be a wrong decision.
>
> I still don't like that much. However, I realize that personal taste
> is a bad reason to hold back a workaround for a long time. I don't
> want to make a wrong decision once more.
>
> It seems not many are interested in it. Here is my ack.
>
> yu ning

Tested and works on real hardware - Asus M2V-MX-SE with SST
SST25VF032B" (4096 KB) SPI flash

Acked-by: Cristi Magherusan

Thanks!
Cristi

[Carl-Daniel Hailfinger]

On 15.05.2009 02:45, Cristi Magherusan wrote:
> On Thu, 2009-05-14 at 22:51 +0800, FENG Yu Ning wrote:
> > Carl-Daniel Hailfinger wrote:
> > > Until the ICH SPI driver can handle preopcodes as standalone opcodes, we
> > > should handle such special opcode failure gracefully on ICH and
> > > compatible chipsets.
> >
> > Acked-by: FENG Yu Ning
> >
> > iirc, Rudolf came to similar solution before, and I tried to hold it
> > back. That might be a wrong decision.
> >
> > I still don't like that much. However, I realize that personal taste
> > is a bad reason to hold back a workaround for a long time. I don't
> > want to make a wrong decision once more.

I'm not too happy about the workaround either. The SPI layer needs some
design changes in the future to better handle this.
> > It seems not many are interested in it. Here is my ack.
> >
> > yu ning
>
> Tested and works on real hardware - Asus M2V-MX-SE with SST
> SST25VF032B" (4096 KB) SPI flash
>
> Acked-by: Cristi Magherusan

Thank you both for reviewing!

Committed in r514.

Regards,
Carl-Daniel