6.6-stable review patch. If anyone has any objections, please let me know.
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From: Frank Li Frank.Li@nxp.com
commit c85e209b799f12d18a90ae6353b997b1bb1274a5 upstream.
MSTATUS[RXPEND] is only updated after the data transfer cycle started. This creates an issue when the I3C clock is slow, and the CPU is running fast enough that MSTATUS[RXPEND] may not be updated when the code reaches checking point. As a result, mandatory data can be missed.
Add a wait for MSTATUS[COMPLETE] to ensure that all mandatory data is already in FIFO. It also works without mandatory data.
Fixes: dd3c52846d59 ("i3c: master: svc: Add Silvaco I3C master driver") Cc: stable@vger.kernel.org Reviewed-by: Miquel Raynal miquel.raynal@bootlin.com Signed-off-by: Frank Li Frank.Li@nxp.com Link: https://lore.kernel.org/r/20231023161658.3890811-4-Frank.Li@nxp.com Signed-off-by: Alexandre Belloni alexandre.belloni@bootlin.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/i3c/master/svc-i3c-master.c | 8 ++++++++ 1 file changed, 8 insertions(+)
--- a/drivers/i3c/master/svc-i3c-master.c +++ b/drivers/i3c/master/svc-i3c-master.c @@ -333,6 +333,7 @@ static int svc_i3c_master_handle_ibi(str struct i3c_ibi_slot *slot; unsigned int count; u32 mdatactrl; + int ret, val; u8 *buf;
slot = i3c_generic_ibi_get_free_slot(data->ibi_pool); @@ -342,6 +343,13 @@ static int svc_i3c_master_handle_ibi(str slot->len = 0; buf = slot->data;
+ ret = readl_relaxed_poll_timeout(master->regs + SVC_I3C_MSTATUS, val, + SVC_I3C_MSTATUS_COMPLETE(val), 0, 1000); + if (ret) { + dev_err(master->dev, "Timeout when polling for COMPLETE\n"); + return ret; + } + while (SVC_I3C_MSTATUS_RXPEND(readl(master->regs + SVC_I3C_MSTATUS)) && slot->len < SVC_I3C_FIFO_SIZE) { mdatactrl = readl(master->regs + SVC_I3C_MDATACTRL);