From: Daniel J Blueman <daniel@quora.org>
To: Mukesh Kumar Savaliya <mukesh.savaliya@oss.qualcomm.com>,
Viken Dadhaniya <viken.dadhaniya@oss.qualcomm.com>,
Andi Shyti <andi.shyti@kernel.org>,
Manikanta Mylavarapu <quic_mmanikan@quicinc.com>,
Bjorn Andersson <andersson@kernel.org>
Cc: linux-i2c@vger.kernel.org, linux-arm-msm@vger.kernel.org,
linux-kernel@vger.kernel.org, stable@vger.kernel.org,
Daniel J Blueman <daniel@quora.org>
Subject: [PATCH] i2c: qcom-geni: restore tSCL with 32MHz I2C fast-mode
Date: Tue, 29 Sep 2026 12:14:43 +0800 [thread overview]
Message-ID: <20260929041444.9837-1-daniel@quora.org> (raw)
Commit cb97bf3d4f91 ("i2c: qcom-geni: Fix hardcoded clock index in
SE_GENI_CLK_SEL") allowed GENI to use 32MHz clock. This changed I2C
timing, making the Yoga Slim 7x keyboard (ITE 048D:8987) unusable
on all boots, and touchpad unusable on some boots, resulting in:
i2c_hid_of 1-003a: unexpected HID descriptor bcdVersion (0x0000)
i2c_hid_of 1-002c: failed to fetch HID descriptor: -110
With this change, t_high_cnt 3 and clk_div 4 gave a tSCL of 375ns
versus the previous default of 521ns, however the I2C spec has a
minimum tSCL of 600ns.
Restore tSCL to the spec with t_high_cnt 5 giving a 625ns tSCL,
verified on Lenovo Yoga Slim 7x X1E-80100.
Fixes: 506bb2ab0075 ("i2c: qcom-geni: Support systems with 32MHz serial engine clock")
Cc: <stable@vger.kernel.org>
Signed-off-by: Daniel J Blueman <daniel@quora.org>
---
drivers/i2c/busses/i2c-qcom-geni.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
index 6a39e21d5ed4..1336a09ca183 100644
--- a/drivers/i2c/busses/i2c-qcom-geni.c
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -193,7 +193,7 @@ static const struct geni_i2c_clk_fld geni_i2c_clk_map_19p2mhz[] = {
/* source_clock = 32 MHz */
static const struct geni_i2c_clk_fld geni_i2c_clk_map_32mhz[] = {
{ I2C_MAX_STANDARD_MODE_FREQ, 12, 9, 10, 26 },
- { I2C_MAX_FAST_MODE_FREQ, 4, 3, 9, 19 },
+ { I2C_MAX_FAST_MODE_FREQ, 4, 5, 9, 19 },
{ I2C_MAX_FAST_MODE_PLUS_FREQ, 2, 3, 5, 15 },
{}
};
--
2.53.0
reply other threads:[~2026-09-29 4:14 UTC|newest]
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