In an In-Band Interrupt (IBI) handle, the code logic is as follows: 1: writel(SVC_I3C_MCTRL_REQUEST_AUTO_IBI | SVC_I3C_MCTRL_IBIRESP_AUTO, master->regs + SVC_I3C_MCTRL); 2: ret = readl_relaxed_poll_timeout(master->regs + SVC_I3C_MSTATUS, val, SVC_I3C_MSTATUS_IBIWON(val), 0, 1000); ... 3: ibitype = SVC_I3C_MSTATUS_IBITYPE(status); ibiaddr = SVC_I3C_MSTATUS_IBIADDR(status); SVC_I3C_MSTATUS_IBIWON may be set before step 1. Thus, step 2 will return immediately, and the I3C controller has not sent out the 9th SCL yet. Consequently, ibitype and ibiaddr are 0, resulting in an unknown IBI type occurrence and missing call I3C client driver's IBI handler. A typical case is that SVC_I3C_MSTATUS_IBIWON is set when an IBI occurs during the controller send start frame in svc_i3c_master_xfer(). Clear SVC_I3C_MSTATUS_IBIWON before issue SVC_I3C_MCTRL_REQUEST_AUTO_IBI to fix this issue. Cc: stable@vger.kernel.org Fixes: 5e5e3c92e748 ("i3c: master: svc: fix wrong data return when IBI happen during start frame") Signed-off-by: Frank Li <Frank.Li@nxp.com> Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/r/20240506164009.21375-3-Frank.Li@nxp.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the reStructuredText markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
Description
Languages
C
97.6%
Assembly
1%
Shell
0.5%
Python
0.3%
Makefile
0.3%