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authorLizhi Hou <lizhi.hou@amd.com>2025-12-04 21:16:03 +0300
committerSasha Levin <sashal@kernel.org>2026-03-04 15:19:49 +0300
commit0e95546a09d2af51dadb2e03cb3cdabb167e148d (patch)
treeffc03cb4e67f3644ef4bcc240c6348b678ed9427 /drivers/accel
parent306378db76a2878c09a0469c959c1a3873c0aaeb (diff)
downloadlinux-0e95546a09d2af51dadb2e03cb3cdabb167e148d.tar.xz
accel/amdxdna: Fix tail-pointer polling in mailbox_get_msg()
[ Upstream commit cd77d5a4aaf8c5c1d819f47cf814bf7d4920b0a2 ] In mailbox_get_msg(), mailbox_reg_read_non_zero() is called to poll for a non-zero tail pointer. This assumed that a zero value indicates an error. However, certain corner cases legitimately produce a zero tail pointer. To handle these cases, remove mailbox_reg_read_non_zero(). The zero tail pointer will be treated as a valid rewind event. Reviewed-by: Maciej Falkowski <maciej.falkowski@linux.intel.com> Signed-off-by: Lizhi Hou <lizhi.hou@amd.com> Link: https://patch.msgid.link/20251204181603.793824-1-lizhi.hou@amd.com Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/accel')
-rw-r--r--drivers/accel/amdxdna/amdxdna_mailbox.c19
1 files changed, 1 insertions, 18 deletions
diff --git a/drivers/accel/amdxdna/amdxdna_mailbox.c b/drivers/accel/amdxdna/amdxdna_mailbox.c
index 8b72cf6bd6e4..469242ed8224 100644
--- a/drivers/accel/amdxdna/amdxdna_mailbox.c
+++ b/drivers/accel/amdxdna/amdxdna_mailbox.c
@@ -112,22 +112,6 @@ static u32 mailbox_reg_read(struct mailbox_channel *mb_chann, u32 mbox_reg)
return readl(ringbuf_addr);
}
-static int mailbox_reg_read_non_zero(struct mailbox_channel *mb_chann, u32 mbox_reg, u32 *val)
-{
- struct xdna_mailbox_res *mb_res = &mb_chann->mb->res;
- void __iomem *ringbuf_addr = mb_res->mbox_base + mbox_reg;
- int ret, value;
-
- /* Poll till value is not zero */
- ret = readx_poll_timeout(readl, ringbuf_addr, value,
- value, 1 /* us */, 100);
- if (ret < 0)
- return ret;
-
- *val = value;
- return 0;
-}
-
static inline void
mailbox_set_headptr(struct mailbox_channel *mb_chann, u32 headptr_val)
{
@@ -291,8 +275,7 @@ static int mailbox_get_msg(struct mailbox_channel *mb_chann)
u32 start_addr;
int ret;
- if (mailbox_reg_read_non_zero(mb_chann, mb_chann->res[CHAN_RES_I2X].mb_tail_ptr_reg, &tail))
- return -EINVAL;
+ tail = mailbox_get_tailptr(mb_chann, CHAN_RES_I2X);
head = mb_chann->i2x_head;
ringbuf_size = mailbox_get_ringbuf_size(mb_chann, CHAN_RES_I2X);
start_addr = mb_chann->res[CHAN_RES_I2X].rb_start_addr;