On Tue, 26 Apr 2022 at 15:50, Eddie James <eajames@xxxxxxxxxxxxx> wrote:
>
> Due to the OCC communication design with a shared SRAM area,
> checkum errors are expected due to corrupted buffer from OCC
> communications with other system components. Therefore, retry
> the command twice in the event of a checksum failure.
>
> Signed-off-by: Eddie James <eajames@xxxxxxxxxxxxx>
> Acked-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> ---
> drivers/hwmon/occ/p9_sbe.c | 15 +++++++++++----
> 1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/hwmon/occ/p9_sbe.c b/drivers/hwmon/occ/p9_sbe.c
> index 49b13cc01073..e6ccef2af659 100644
> --- a/drivers/hwmon/occ/p9_sbe.c
> +++ b/drivers/hwmon/occ/p9_sbe.c
> @@ -14,6 +14,8 @@
>
> #include "common.h"
>
> +#define OCC_CHECKSUM_RETRIES 3
> +
> struct p9_sbe_occ {
> struct occ occ;
> bool sbe_error;
> @@ -83,17 +85,22 @@ static int p9_sbe_occ_send_cmd(struct occ *occ, u8 *cmd, size_t len)
> struct occ_response *resp = &occ->resp;
> struct p9_sbe_occ *ctx = to_p9_sbe_occ(occ);
> size_t resp_len = sizeof(*resp);
> + int i;
> int rc;
>
> - rc = fsi_occ_submit(ctx->sbe, cmd, len, resp, &resp_len);
> - if (rc < 0) {
> + for (i = 0; i < OCC_CHECKSUM_RETRIES; ++i) {
> + rc = fsi_occ_submit(ctx->sbe, cmd, len, resp, &resp_len);
> + if (rc >= 0)
> + break;
> if (resp_len) {
> if (p9_sbe_occ_save_ffdc(ctx, resp, resp_len))
> sysfs_notify(&occ->bus_dev->kobj, NULL,
> bin_attr_ffdc.attr.name);
> - }
>
> - return rc;
> + return rc;
> + }
> + if (rc != -EBADE)
> + return rc;
Future you might appreciate a comment above the EBADE check clarifying
why that error is being special cased.
> }
>
> switch (resp->return_status) {
> --
> 2.27.0
>
