qemu/include/hw/i2c/smbus_eeprom.h
Markus Armbruster f26740c61a smbus: Fix spd_data_generate() error API violation
The Error ** argument must be NULL, &error_abort, &error_fatal, or a
pointer to a variable containing NULL.  Passing an argument of the
latter kind twice without clearing it in between is wrong: if the
first call sets an error, it no longer points to NULL for the second
call.

spd_data_generate() can pass @errp to error_setg() more than once when
it adjusts both memory size and type.  Harmless, because no caller
passes anything that needs adjusting.  Until the previous commit,
sam460ex passed types that needed adjusting, but not sizes.

spd_data_generate()'s contract is rather awkward:

    If everything's fine, return non-null and don't set an error.

    Else, if memory size or type need adjusting, return non-null and
    set an error describing the adjustment.

    Else, return null and set an error reporting why no data can be
    generated.

Its callers treat the error as a warning even when null is returned.
They don't create the "smbus-eeprom" device then.  Suspicious.

Since the previous commit, only "everything's fine" can actually
happen.  Drop the unused code and simplify the callers.  This gets rid
of the error API violation.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200422134815.1584-3-armbru@redhat.com>
2020-04-29 08:01:52 +02:00

37 lines
1.5 KiB
C

/*
* QEMU SMBus EEPROM API
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef HW_SMBUS_EEPROM_H
#define HW_SMBUS_EEPROM_H
#include "exec/cpu-common.h"
#include "hw/i2c/i2c.h"
void smbus_eeprom_init_one(I2CBus *bus, uint8_t address, uint8_t *eeprom_buf);
void smbus_eeprom_init(I2CBus *bus, int nb_eeprom,
const uint8_t *eeprom_spd, int size);
enum sdram_type { SDR = 0x4, DDR = 0x7, DDR2 = 0x8 };
uint8_t *spd_data_generate(enum sdram_type type, ram_addr_t size);
#endif