Re: [PATCH v2] mmc: core: Return correct emmc response in case of ioctl error

[Nishad Kamdar]

On Mon, Aug 09, 2021 at 08:41:19AM +0000, Avri Altman wrote:
> > When a read/write command is sent via ioctl to the kernel,
> > and the command fails, the actual error response of the emmc
> > is not sent to the user.
> > 
> > Following are the tests carried out using commands
> > 17 (Single BLock Read),
> > 24 (Single Block Write),
> > 18 (Multi Block Read),
> > 25 (Multi Block Write)
> > 
> > The tests are carried out on a 64Gb emmc device. All of these
> > tests try to access an "out of range" sector address (0x09B2FFFF).
> > 
> > It is seen that without the patch the response received by the user
> > is not OUT_OF_RANGE error (R1 response 31st bit is not set) as per
> > JEDEC specification. After applying the patch proper response is seen.
> > 
> > The user level ioctl testcode for the above commands and their
> > respective outputs without and with the patch are shown below:
> > 
> > CMD17 (Test Code Snippet):
> > ==========================
> >         printf("Forming CMD%d\n", opt_idx);
> >         /*  single block read */
> >         cmd.blksz = 512;
> >         cmd.blocks = 1;
> >         cmd.write_flag = 0;
> >         cmd.opcode = 17;
> >         //cmd.arg = atoi(argv[3]);
> >         cmd.arg = 0x09B2FFFF;
> >         /* Expecting response R1B */
> >         cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
> > 
> >         memset(data, 0, sizeof(__u8) * 512);
> >         mmc_ioc_cmd_set_data(cmd, data);
> > 
> >         printf("Sending CMD%d: ARG[0x%08x]\n", opt_idx, cmd.arg);
> >         if(ioctl(fd, MMC_IOC_CMD, &cmd))
> >                 perror("Error");
> > 
> >         printf("\nResponse: %08x\n", cmd.response[0]);
> > 
> > CMD17 (Output without patch):
> > =============================
> > test@test-LIVA-Z:~$ sudo ./mmc cmd_test /dev/mmcblk0 17 09B2FFFF
> No need for arg 3 - you are hardcoded overriding it.
> 
> > Entering the do_mmc_commands:Device: /dev/mmcblk0 nargs:4
> > Entering the do_mmc_commands:Device: /dev/mmcblk0 options[17,
> > 0x09B2FFF]
> > Forming CMD17
> > Sending CMD17: ARG[0x09b2ffff]
> > Error: Connection timed out
> > 
> > Response: 00000000  (Wrong response)
> > 
> > CMD17 (Output with patch):
> > ==========================
> > test@test-LIVA-Z:~$ sudo ./mmc cmd_test /dev/mmcblk0 17 09B2FFFF
> > [sudo] password for test:
> > Entering the do_mmc_commands:Device: /dev/mmcblk0 nargs:4
> > Entering the do_mmc_commands:Device: /dev/mmcblk0 options[17, 09B2FFFF]
> > Forming CMD17
> > Sending CMD17: ARG[0x09b2ffff]
> > Error: Connection timed out
> > 
> > Response: 80000900
> > (Correct OUT_OF_ERROR response as per JEDEC specification)
> 
> 
> > 
> > CMD24 (Test Code Snippet):
> > ==========================
> >         printf("Forming CMD%d\n", opt_idx);
> >         cmd.opcode = 24;
> >         //cmd.arg = atoi(argv[3]);
> >         cmd.arg = 0x09B2FFFF;
> >         cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
> >         cmd.blksz = 512;
> >         cmd.blocks = 1;
> >         cmd.write_flag = 1;
> > 
> >         memset(data, 0xA5, sizeof(__u8) * 512);
> >         mmc_ioc_cmd_set_data(cmd, data);
> > 
> >         printf("Sending CMD%d: ARG[0x%08x]\n", opt_idx, cmd.arg);
> >         if(ioctl(fd, MMC_IOC_CMD, &cmd))
> >                 perror("Error");
> > 
> >         printf("\nResponse: %08x\n", cmd.response[0]);
> > 
> > CMD24 (Output without patch):
> > =============================
> > test@test-LIVA-Z:~$ sudo ./mmc cmd_test /dev/mmcblk0 24 0x09B2FFF
> > [sudo] password for test:
> > Entering the do_mmc_commands:Device: /dev/mmcblk0 nargs:4
> > Entering the do_mmc_commands:Device: /dev/mmcblk0 options[24,
> > 0x09B2FFF]
> > Forming CMD24
> > Sending CMD24: ARG[0x09b2ffff]
> > Error: Connection timed out
> > 
> > Response: 00000000 (Incorrect response)
> > 
> > CMD24 (Output with patch):
> > ==========================
> > test@test-LIVA-Z:~$ sudo ./mmc cmd_test /dev/mmcblk0 24 09B2FFFF
> > Entering the do_mmc_commands:Device: /dev/mmcblk0 nargs:4
> > Entering the do_mmc_commands:Device: /dev/mmcblk0 options[24, 09B2FFFF]
> > Forming CMD24
> > Sending CMD24: ARG[0x09b2ffff]
> > Error: Connection timed out
> > 
> > Response: 80000900
> > (Correct OUT_OF_RANGE response as per JEDEC specification)
> > 
> > CMD18 (Test Code Snippet):
> > ==========================
> >         printf("Forming CMD%d\n", opt_idx);
> > 
> >         cmd.blksz = 512;
> >         cmd.blocks = 1;
> >         cmd.write_flag = 0;
> >         cmd.opcode = 18;
> >         //cmd.arg = atoi(argv[3]);
> >         cmd.arg = 0x09B2FFFF;
> > 
> >         cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
> > 
> >         memset(data, 0, sizeof(__u8) * 512);
> >         mmc_ioc_cmd_set_data(cmd, data);
> > 
> >         printf("Sending CMD%d: ARG[0x%08x]\n", opt_idx, cmd.arg);
> >         if(ioctl(fd, MMC_IOC_CMD, &cmd)) {
> >                 printf(" error ioctl \n");
> >                 perror("Error");
> >         }
> > 
> >         printf("\nResponse: %08x\n", cmd.response[0]);
> > 
> > CMD18 (Output without patch):
> > =============================
> > test@test-LIVA-Z:~$ sudo ./mmc cmd_test /dev/mmcblk0 18 0x09B2FFF
> > Entering the do_mmc_commands:Device: /dev/mmcblk0 nargs:4
> > Entering the do_mmc_commands:Device: /dev/mmcblk0 options[18,
> > 0x09B2FFF]
> > Forming CMD18
> > Sending CMD18: ARG[0x09b2ffff]
> >  error ioctl
> > Error: Connection timed out
> > 
> > Response: 00000000 (Incorrect response)
> > 
> > CMD18 (Output with patch):
> > ==========================
> > test@test-LIVA-Z:~$ sudo ./mmc cmd_test /dev/mmcblk0 18 09B2FFFF
> > Entering the do_mmc_commands:Device: /dev/mmcblk0 nargs:4
> > Entering the do_mmc_commands:Device: /dev/mmcblk0 options[18, 09B2FFFF]
> > Forming CMD18
> > Sending CMD18: ARG[0x09b2ffff]
> >  error ioctl
> > Error: Connection timed out
> > 
> > Response: 80000900
> > (Correct OUT_OF_RANGE response as per JEDEC specification)
> > 
> > CMD25 (Test Code Snippet):
> > ==========================
> >         printf("Forming CMD%d\n", opt_idx);
> >         cmd.opcode = 25;
> >         //cmd.arg = atoi(argv[3]);
> >         cmd.arg = 0x09B2FFFF;
> >         cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
> > 
> >         cmd.blksz = 512;
> >         cmd.blocks = 1;
> >         cmd.write_flag = 1;
> > 
> >         memset(data, 0xA5, sizeof(__u8) * 512);
> >         mmc_ioc_cmd_set_data(cmd, data);
> > 
> >         printf("Sending CMD%d: ARG[0x%08x]\n", opt_idx, cmd.arg);
> >         if(ioctl(fd, MMC_IOC_CMD, &cmd)) {
> >                 printf("\nerror ioctl\n");
> >                 perror("Error");
> >         }
> > 
> >         printf("\nResponse: %08x\n", cmd.response[0]);
> > 
> > CMD25 (Output without patch):
> > =============================
> > test@test-LIVA-Z:~$ sudo ./mmc cmd_test /dev/mmcblk0 25 0x09B2FFF
> > Entering the do_mmc_commands:Device: /dev/mmcblk0 nargs:4
> > Entering the do_mmc_commands:Device: /dev/mmcblk0 options[25,
> > 0x09B2FFF]
> > Forming CMD25
> > Sending CMD25: ARG[0x09b2ffff]
> > 
> > error ioctl
> > Error: Connection timed out
> > 
> > Response: 00000000 (Incorrect response)
> > 
> > CMD25 (Output with patch):
> > ==========================
> > test@test-LIVA-Z:~$ sudo ./mmc cmd_test /dev/mmcblk0 25 09B2FFFF
> > Entering the do_mmc_commands:Device: /dev/mmcblk0 nargs:4
> > Entering the do_mmc_commands:Device: /dev/mmcblk0 options[25, 09B2FFFF]
> > Forming CMD25
> > Sending CMD25: ARG[0x09b2ffff]
> > 
> > error ioctl
> > Error: Connection timed out
> > 
> > Response: 80000900
> > (Correct OUT_OF_RANGE response as per JEDEC specification)
> > 
> > Signed-off-by: Nishad Kamdar <nishadkamdar@xxxxxxxxx>
> Reviewed-by: Avri Altman <avri.altman@xxxxxxx>
> 
> > ---
> > Changes in v2:
> >   - Make commit message clearer by adding test cases as outputs
> A little overwhelming IMO
> 
Ok, Thanks for the review and comments.

Regards,
Nishad
> > 
> >  drivers/mmc/core/block.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
> > index a9ad9f5fa9491..efa92aa7e2368 100644
> > --- a/drivers/mmc/core/block.c
> > +++ b/drivers/mmc/core/block.c
> > @@ -522,11 +522,13 @@ static int __mmc_blk_ioctl_cmd(struct mmc_card
> > *card, struct mmc_blk_data *md,
> >         if (cmd.error) {
> >                 dev_err(mmc_dev(card->host), "%s: cmd error %d\n",
> >                                                 __func__, cmd.error);
> > +               memcpy(&idata->ic.response, cmd.resp, sizeof(cmd.resp));
> >                 return cmd.error;
> >         }
> >         if (data.error) {
> >                 dev_err(mmc_dev(card->host), "%s: data error %d\n",
> >                                                 __func__, data.error);
> > +               memcpy(&idata->ic.response, cmd.resp, sizeof(cmd.resp));
> >                 return data.error;
> >         }
> > 
> > --
> > 2.17.1
>