Hello Tomas, On 15.08.24 07:53, Tomas Marek wrote: > Hello Ahmad, > > Thanks for maintenance of the Barebox EFI. > > On Wed, Aug 14, 2024 at 11:24:23AM +0200, Ahmad Fatoum wrote: >> I2C message length is 16 bit, so doing a 64-bit division is overkill. >> Let's remove the cast and just rely on the usual integer promotion >> to 32-bit. >> >> Cc: Tomas Marek <tomas.marek@xxxxxxxxx> >> Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> >> --- >> drivers/i2c/busses/i2c-efi.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/i2c/busses/i2c-efi.c b/drivers/i2c/busses/i2c-efi.c >> index 5f6cc0eed28e..a666a28fab51 100644 >> --- a/drivers/i2c/busses/i2c-efi.c >> +++ b/drivers/i2c/busses/i2c-efi.c >> @@ -114,7 +114,7 @@ static unsigned int efi_i2c_msg_op_cnt(const struct efi_i2c_priv *i2c_priv, >> >> max_len = efi_i2c_max_len(i2c_priv, msg); >> >> - return ((u64)msg->len + max_len - 1) / max_len; >> + return (msg->len + max_len - 1) / max_len; > > The issue here is that max_len, which represents the MaximumReceiveBytes > or MaximumTransmitBytes in EFI I2C capabilities, is 32-bit. In some EFI > implementations (including the one I use), the EFI I2C MaximumReceiveBytes > and MaximumTransmitBytes are set to the maximum value (0xFFFFFFFF). This > causes msg->len + max_len - 1 to overflow, leading to an incorrect number > of returned operations. To address this, the msg->len is extended to 64 bits. Thanks for the info. See the patch I just Cc'd you on. @Sascha, can you drop this one patch again? Thanks, Ahmad > > Best regards > > Tomas > >> } >> >> static unsigned int efi_i2c_req_op_cnt( >> -- >> 2.39.2 >> > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
