@samitouri / QOSamiQemu / commits / 4957f668c4

hw/block: m25p80: Fix dummy byte handling for Spansion flash

Spansion flashes expose the number of dummy clock cycles through CR2V register [1]. The value is a cycle count, not a byte count, so the m25p80 model has to convert it to the number of whole SSI transfer bytes consumed while collecting read command data. Add a helper that multiplies the CR2V dummy cycle count by the phase width and rounds up non-byte-aligned counts, matching the byte-oriented SSI model. The default eight-cycle configuration keeps the same byte counts as before. [1] https://www.infineon.com/assets/row/public/documents/10/49/infineon-s25fs128s-s25fs256s-1-datasheet-en.pdf Fixes: cf6f1efe0b57 ("m25p80: Fast read commands family changes") Signed-off-by: Bin Meng <bin.meng@processmission.com> Tested-by: Cédric Le Goater <clg@redhat.com> Message-ID: <20260707083431.219671-5-bin.meng@processmission.com> Signed-off-by: Philippe Mathieu-Daudé <philmd@oss.qualcomm.com>

Bin Meng committed Jul 7, 2026 at 16:34 UTC 4957f668c4369f6b80e77b04e604747ca6014c9a

1 file changed +20 -12

hw/block/m25p80.c

+20 -12

@@ -1057,6 +1057,23 @@ static uint8_t macronix_extract_cfg_dummy_bytes(Flash *s, uint8_t bus_width)

1057 return dummy_bits / 8;

1058 }

1059

1060 +static uint8_t spansion_extract_cfg_dummy_bytes(Flash *s, uint8_t bus_width)

1061 +{

1062 + uint8_t dummy_bits;

1063 +

1064 + dummy_bits = extract32(s->spansion_cr2v, SPANSION_DUMMY_CLK_POS,

1065 + SPANSION_DUMMY_CLK_LEN);

1066 + dummy_bits *= bus_width;

1067 +

1068 + /*

1069 + * Assert that the dummy bit count is byte-aligned

1070 + * as SSI core can only consume whole dummy bytes.

1071 + */

1072 + assert(dummy_bits % 8 == 0);

1073 +

1074 + return dummy_bits / 8;

1075 +}

1076 +

1077 static void decode_fast_read_cmd(Flash *s)

1078 {

1079 s->needed_bytes = get_addr_length(s);

@@ -1075,10 +1092,7 @@ static void decode_fast_read_cmd(Flash *s)

1092 s->needed_bytes += macronix_extract_cfg_dummy_bytes(s, 1);

1093 break;

1094 case MAN_SPANSION:

1078 - s->needed_bytes += extract32(s->spansion_cr2v,

1079 - SPANSION_DUMMY_CLK_POS,

1080 - SPANSION_DUMMY_CLK_LEN

1081 - );

1095 + s->needed_bytes += spansion_extract_cfg_dummy_bytes(s, 1);

1096 break;

1097 case MAN_ISSI:

1098 /*

@@ -1111,10 +1125,7 @@ static void decode_dio_read_cmd(Flash *s)

1125 break;

1126 case MAN_SPANSION:

1127 s->needed_bytes += SPANSION_CONTINUOUS_READ_MODE_CMD_LEN;

1114 - s->needed_bytes += extract32(s->spansion_cr2v,

1115 - SPANSION_DUMMY_CLK_POS,

1116 - SPANSION_DUMMY_CLK_LEN

1117 - );

1128 + s->needed_bytes += spansion_extract_cfg_dummy_bytes(s, 2);

1129 break;

1130 case MAN_NUMONYX:

1131 s->needed_bytes += numonyx_extract_cfg_dummy_bytes(s);

@@ -1151,10 +1162,7 @@ static void decode_qio_read_cmd(Flash *s)

1162 break;

1163 case MAN_SPANSION:

1164 s->needed_bytes += SPANSION_CONTINUOUS_READ_MODE_CMD_LEN;

1154 - s->needed_bytes += extract32(s->spansion_cr2v,

1155 - SPANSION_DUMMY_CLK_POS,

1156 - SPANSION_DUMMY_CLK_LEN

1157 - );

1165 + s->needed_bytes += spansion_extract_cfg_dummy_bytes(s, 4);

1166 break;

1167 case MAN_NUMONYX:

1168 s->needed_bytes += numonyx_extract_cfg_dummy_bytes(s);