2022-03-03 17:10:35

by Mario Limonciello

Subject: [PATCH v2 1/5] thunderbolt: Retry DROM reads for more failure scenarios

Currently DROM reads are only retried in the case that parsing failed.
However if the size or CRC fails, then there should also be a retry.

This helps with reading the DROM on TBT3 devices connected to AMD
Yellow Carp which will sometimes fail on the first attempt.

Signed-off-by: Mario Limonciello <[email protected]>
---
v1->v2:
* Update commit message
drivers/thunderbolt/eeprom.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/thunderbolt/eeprom.c b/drivers/thunderbolt/eeprom.c
index 470885e6f1c8..10cdbcb55df9 100644
--- a/drivers/thunderbolt/eeprom.c
+++ b/drivers/thunderbolt/eeprom.c
@@ -553,9 +553,9 @@ static int tb_drom_parse(struct tb_switch *sw)
crc = tb_crc8((u8 *) &header->uid, 8);
if (crc != header->uid_crc8) {
tb_sw_warn(sw,
- "DROM UID CRC8 mismatch (expected: %#x, got: %#x), aborting\n",
+ "DROM UID CRC8 mismatch (expected: %#x, got: %#x)\n",
header->uid_crc8, crc);
- return -EINVAL;
+ return -EILSEQ;
}
if (!sw->uid)
sw->uid = header->uid;
@@ -654,6 +654,7 @@ int tb_drom_read(struct tb_switch *sw)
sw->drom = kzalloc(size, GFP_KERNEL);
if (!sw->drom)
return -ENOMEM;
+read:
res = tb_drom_read_n(sw, 0, sw->drom, size);
if (res)
goto err;
@@ -662,7 +663,11 @@ int tb_drom_read(struct tb_switch *sw)
header = (void *) sw->drom;

if (header->data_len + TB_DROM_DATA_START != size) {
- tb_sw_warn(sw, "drom size mismatch, aborting\n");
+ tb_sw_warn(sw, "drom size mismatch\n");
+ if (retries--) {
+ msleep(100);
+ goto read;
+ }
goto err;
}

@@ -683,11 +688,9 @@ int tb_drom_read(struct tb_switch *sw)

/* If the DROM parsing fails, wait a moment and retry once */
if (res == -EILSEQ && retries--) {
- tb_sw_warn(sw, "parsing DROM failed, retrying\n");
+ tb_sw_warn(sw, "parsing DROM failed\n");
msleep(100);
- res = tb_drom_read_n(sw, 0, sw->drom, size);
- if (!res)
- goto parse;
+ goto read;
}

if (!res)
--
2.34.1

2022-03-04 20:30:11

by Mika Westerberg

Subject: Re: [PATCH v2 1/5] thunderbolt: Retry DROM reads for more failure scenarios

Hi Mario,

On Thu, Mar 03, 2022 at 07:13:24AM -0600, Mario Limonciello wrote:
> Currently DROM reads are only retried in the case that parsing failed.
> However if the size or CRC fails, then there should also be a retry.
>
> This helps with reading the DROM on TBT3 devices connected to AMD
> Yellow Carp which will sometimes fail on the first attempt.
>
> Signed-off-by: Mario Limonciello <[email protected]>

This and the rest of the patches applied to thunderbolt.git/next,
thanks!