diff options
| author | Patrick Venture <venture@google.com> | 2021-12-20 13:21:37 -0800 |
|---|---|---|
| committer | Philippe Mathieu-Daudé <f4bug@amsat.org> | 2022-03-14 14:48:35 +0100 |
| commit | 1cbab82e9d1bdb2c7b9ef46a396fdc03ea3fa04c (patch) | |
| tree | 6158086c0e3a76b58993f03fb390f35e3d0236bc /hw | |
| parent | 15df33ceb73cb6bb3c6736cf4d2cff51129ed4b4 (diff) | |
hw/nvram: at24 return 0xff if 1 byte address
The at24 eeproms are 2 byte devices that return 0xff when they are read
from with a partial (1-byte) address written. This distinction was
found comparing model behavior to real hardware testing.
Tested: `i2ctransfer -f -y 45 w1@85 0 r1` returns 0xff instead of next
byte
Signed-off-by: Patrick Venture <venture@google.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20211220212137.1244511-1-venture@google.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Diffstat (limited to 'hw')
| -rw-r--r-- | hw/nvram/eeprom_at24c.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/hw/nvram/eeprom_at24c.c b/hw/nvram/eeprom_at24c.c index da435500ba..01a3093600 100644 --- a/hw/nvram/eeprom_at24c.c +++ b/hw/nvram/eeprom_at24c.c @@ -58,9 +58,10 @@ int at24c_eeprom_event(I2CSlave *s, enum i2c_event event) switch (event) { case I2C_START_SEND: - case I2C_START_RECV: case I2C_FINISH: ee->haveaddr = 0; + /* fallthrough */ + case I2C_START_RECV: DPRINTK("clear\n"); if (ee->blk && ee->changed) { int len = blk_pwrite(ee->blk, 0, ee->mem, ee->rsize, 0); @@ -84,6 +85,10 @@ uint8_t at24c_eeprom_recv(I2CSlave *s) EEPROMState *ee = AT24C_EE(s); uint8_t ret; + if (ee->haveaddr == 1) { + return 0xff; + } + ret = ee->mem[ee->cur]; ee->cur = (ee->cur + 1u) % ee->rsize; |