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envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=66.111.4.26; envelope-from=peter@pjd.dev; helo=out2-smtp.messagingengine.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1674009834015100007 Content-Type: text/plain; charset="utf-8" EEPROM's are a form of non-volatile memory. After power-cycling an EEPROM, I would expect the I2C state machine to be reset to default values, but I wouldn't really expect the memory to change at all. The current implementation of the at24c EEPROM resets its internal memory on reset. This matches the specification in docs/devel/reset.rst: Cold reset is supported by every resettable object. In QEMU, it means we = reset to the initial state corresponding to the start of QEMU; this might differ from what is a real hardware cold reset. It differs from other resets (li= ke warm or bus resets) which may keep certain parts untouched. But differs from my intuition. For example, if someone writes some informat= ion to an EEPROM, then AC power cycles their board, they would expect the EEPRO= M to retain that information. It's very useful to be able to test things like th= is in QEMU as well, to verify software instrumentation like determining the ca= use of a reboot. Fixes: 5d8424dbd3e8 ("nvram: add AT24Cx i2c eeprom") Signed-off-by: Peter Delevoryas Reviewed-by: Joel Stanley Reviewed-by: Corey Minyard Reviewed-by: C=C3=A9dric Le Goater --- hw/nvram/eeprom_at24c.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/hw/nvram/eeprom_at24c.c b/hw/nvram/eeprom_at24c.c index f8d751fa278d..5074776bff04 100644 --- a/hw/nvram/eeprom_at24c.c +++ b/hw/nvram/eeprom_at24c.c @@ -185,18 +185,6 @@ static void at24c_eeprom_realize(DeviceState *dev, Err= or **errp) } =20 ee->mem =3D g_malloc0(ee->rsize); - -} - -static -void at24c_eeprom_reset(DeviceState *state) -{ - EEPROMState *ee =3D AT24C_EE(state); - - ee->changed =3D false; - ee->cur =3D 0; - ee->haveaddr =3D 0; - memset(ee->mem, 0, ee->rsize); =20 if (ee->init_rom) { @@ -214,6 +202,16 @@ void at24c_eeprom_reset(DeviceState *state) } } =20 +static +void at24c_eeprom_reset(DeviceState *state) +{ + EEPROMState *ee =3D AT24C_EE(state); + + ee->changed =3D false; + ee->cur =3D 0; + ee->haveaddr =3D 0; +} + static Property at24c_eeprom_props[] =3D { DEFINE_PROP_UINT32("rom-size", EEPROMState, rsize, 0), DEFINE_PROP_BOOL("writable", EEPROMState, writable, true), --=20 2.39.0