Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
accel/amdxdna: Fix tail-pointer polling in mailbox_get_msg()
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
+1
-18
+1
-18
drivers/accel/amdxdna/amdxdna_mailbox.c
+1
-18
drivers/accel/amdxdna/amdxdna_mailbox.c
···
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return readl(ringbuf_addr);
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}
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115
-
static int mailbox_reg_read_non_zero(struct mailbox_channel *mb_chann, u32 mbox_reg, u32 *val)
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-
{
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struct xdna_mailbox_res *mb_res = &mb_chann->mb->res;
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void __iomem *ringbuf_addr = mb_res->mbox_base + mbox_reg;
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int ret, value;
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-
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/* Poll till value is not zero */
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ret = readx_poll_timeout(readl, ringbuf_addr, value,
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value, 1 /* us */, 100);
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if (ret < 0)
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return ret;
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-
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*val = value;
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return 0;
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}
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-
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static inline void
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mailbox_set_headptr(struct mailbox_channel *mb_chann, u32 headptr_val)
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{
···
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u32 start_addr;
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int ret;
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if (mailbox_reg_read_non_zero(mb_chann, mb_chann->res[CHAN_RES_I2X].mb_tail_ptr_reg, &tail))
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return -EINVAL;
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+
tail = mailbox_get_tailptr(mb_chann, CHAN_RES_I2X);
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head = mb_chann->i2x_head;
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ringbuf_size = mailbox_get_ringbuf_size(mb_chann, CHAN_RES_I2X);
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start_addr = mb_chann->res[CHAN_RES_I2X].rb_start_addr;