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authorMika Westerberg <mika.westerberg@linux.intel.com>2020-09-07 12:20:36 +0300
committerMika Westerberg <mika.westerberg@linux.intel.com>2020-09-09 14:00:56 +0300
commitf022ff7bf377ca94367be05de61277934d42ea74 (patch)
tree27457062ea9819cfda2933c8b05159486ae189aa
parent813050e0a9b871ac575abfd3d321f74916df609d (diff)
downloadlinux-f022ff7bf377ca94367be05de61277934d42ea74.tar.gz
linux-f022ff7bf377ca94367be05de61277934d42ea74.tar.xz
thunderbolt: Retry DROM read once if parsing fails
Kai-Heng reported that sometimes DROM parsing of ASUS PA27AC Thunderbolt 3 monitor fails. This makes the driver to fail to add the device so only DisplayPort tunneling is functional. It is not clear what exactly happens but waiting for 100 ms and retrying the read seems to work this around so we do that here. Link: https://bugzilla.kernel.org/show_bug.cgi?id=206493 Reported-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Cc: stable@vger.kernel.org Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
-rw-r--r--drivers/thunderbolt/eeprom.c20
1 files changed, 16 insertions, 4 deletions
diff --git a/drivers/thunderbolt/eeprom.c b/drivers/thunderbolt/eeprom.c
index 3ebca44ab3fa..0c8471be3e32 100644
--- a/drivers/thunderbolt/eeprom.c
+++ b/drivers/thunderbolt/eeprom.c
@@ -7,6 +7,7 @@
*/
#include <linux/crc32.h>
+#include <linux/delay.h>
#include <linux/property.h>
#include <linux/slab.h>
#include "tb.h"
@@ -389,8 +390,8 @@ static int tb_drom_parse_entries(struct tb_switch *sw)
struct tb_drom_entry_header *entry = (void *) (sw->drom + pos);
if (pos + 1 == drom_size || pos + entry->len > drom_size
|| !entry->len) {
- tb_sw_warn(sw, "drom buffer overrun, aborting\n");
- return -EIO;
+ tb_sw_warn(sw, "DROM buffer overrun\n");
+ return -EILSEQ;
}
switch (entry->type) {
@@ -526,7 +527,8 @@ int tb_drom_read(struct tb_switch *sw)
u16 size;
u32 crc;
struct tb_drom_header *header;
- int res;
+ int res, retries = 1;
+
if (sw->drom)
return 0;
@@ -612,7 +614,17 @@ parse:
tb_sw_warn(sw, "drom device_rom_revision %#x unknown\n",
header->device_rom_revision);
- return tb_drom_parse_entries(sw);
+ res = tb_drom_parse_entries(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");
+ msleep(100);
+ res = tb_drom_read_n(sw, 0, sw->drom, size);
+ if (!res)
+ goto parse;
+ }
+
+ return res;
err:
kfree(sw->drom);
sw->drom = NULL;