Re: [PATCH] clk: qcom: camcc-sdm845/670: Raise CSIPHY timer clock limit

From: Konrad Dybcio

Date: Wed Sep 02 2026 - 06:43:53 EST


On 8/22/26 4:25 AM, David Heidelberg via B4 Relay wrote:
> From: David Heidelberg <david@xxxxxxx>
>
> The sdm845 CSIPHY timer clock only listed up to 269.33 MHz, capping the
> supported CSI link frequency at roughly 1.07 GHz
> (CSIPHY timer = link_freq / 4). The Samsung S5K2X7SP camera runs at a
> 1.15 GHz link frequency, so camss rejected powering up the
> pipeline with 'Pixel clock is too high for CSIPHY'.
>
> Add a 288 MHz entry to the shared camcc CSIPHY timer frequency table
> (PLL1 VCO 1152 MHz, well within range) and add a 400 MHz entry to the
> sdm845 CSIPHY timer clock_rate tables. The camss min_rate check now
> passes and the timer clock rounds to 288 MHz, matching the ~287.5 MHz
> required by the 1.15 GHz link.
>
> Assisted-by: tencent:hy3
> Signed-off-by: David Heidelberg <david@xxxxxxx>
> ---
> Tested on SHIFT 6MQ with next-20260820.

Is that what happens on downstream for this device too? Is there a
chance the sensor link frequency can be lowered?

Generally the latest clock plan for SDM845 says that 269.333 MHz is
a maximum, with the RPMHPD running at TURBO.. I would assume that
while the PLL rate stays the same, the downstream branches and RCGs
may not have been validated to properly function at these freqs

Konrad