diff options
| author | Stanley Chu <yschu@nuvoton.com> | 2025-07-30 08:37:19 +0800 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2025-07-31 01:36:16 +0200 |
| commit | bc4a09d8e79cadccdd505f47b01903a80bc666e7 (patch) | |
| tree | ecfce86343e82eea1f665b51e44ff89a5e68bc76 | |
| parent | d028219a9f1485914492bf373406f6a0e665ace2 (diff) | |
i3c: master: svc: Fix npcm845 FIFO_EMPTY quirk
In a private write transfer, the driver pre-fills the FIFO to work around
the FIFO_EMPTY quirk. However, if an IBIWON event occurs, the hardware
emits a NACK and the driver initiates a retry. During the retry, driver
attempts to pre-fill the FIFO again if there is remaining data, but since
the FIFO is already full, this leads to data loss.
Check available space in FIFO to prevent overflow.
Fixes: 4008a74e0f9b ("i3c: master: svc: Fix npcm845 FIFO empty issue")
Signed-off-by: Stanley Chu <yschu@nuvoton.com>
Link: https://lore.kernel.org/r/20250730003719.1825593-1-yschu@nuvoton.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
| -rw-r--r-- | drivers/i3c/master/svc-i3c-master.c | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c index 6d0eea80ea34..b2b5db3ed5bb 100644 --- a/drivers/i3c/master/svc-i3c-master.c +++ b/drivers/i3c/master/svc-i3c-master.c @@ -104,6 +104,7 @@ #define SVC_I3C_MDATACTRL_TXTRIG_FIFO_NOT_FULL GENMASK(5, 4) #define SVC_I3C_MDATACTRL_RXTRIG_FIFO_NOT_EMPTY 0 #define SVC_I3C_MDATACTRL_RXCOUNT(x) FIELD_GET(GENMASK(28, 24), (x)) +#define SVC_I3C_MDATACTRL_TXCOUNT(x) FIELD_GET(GENMASK(20, 16), (x)) #define SVC_I3C_MDATACTRL_TXFULL BIT(30) #define SVC_I3C_MDATACTRL_RXEMPTY BIT(31) @@ -1304,14 +1305,19 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master, * FIFO start filling as soon as possible after EmitStartAddr. */ if (svc_has_quirk(master, SVC_I3C_QUIRK_FIFO_EMPTY) && !rnw && xfer_len) { - u32 end = xfer_len > SVC_I3C_FIFO_SIZE ? 0 : SVC_I3C_MWDATAB_END; - u32 len = min_t(u32, xfer_len, SVC_I3C_FIFO_SIZE); - - writesb(master->regs + SVC_I3C_MWDATAB1, out, len - 1); - /* Mark END bit if this is the last byte */ - writel(out[len - 1] | end, master->regs + SVC_I3C_MWDATAB); - xfer_len -= len; - out += len; + u32 space, end, len; + + reg = readl(master->regs + SVC_I3C_MDATACTRL); + space = SVC_I3C_FIFO_SIZE - SVC_I3C_MDATACTRL_TXCOUNT(reg); + if (space) { + end = xfer_len > space ? 0 : SVC_I3C_MWDATAB_END; + len = min_t(u32, xfer_len, space); + writesb(master->regs + SVC_I3C_MWDATAB1, out, len - 1); + /* Mark END bit if this is the last byte */ + writel(out[len - 1] | end, master->regs + SVC_I3C_MWDATAB); + xfer_len -= len; + out += len; + } } ret = readl_poll_timeout(master->regs + SVC_I3C_MSTATUS, reg, |