Re: [PATCH v4 1/4] PCI: rockchip: drop 2.5 GT/s defines

From: Geraldo Nascimento <geraldogabriel@gmail.com>
To: Charalampos Mitrodimas <charmitro@posteo.net>
Cc: "Shawn Lin" <shawn.lin@rock-chips.com>,
	"Lorenzo Pieralisi" <lpieralisi@kernel.org>,
	"Krzysztof Wilczyński" <kwilczynski@kernel.org>,
	"Manivannan Sadhasivam" <mani@kernel.org>,
	"Rob Herring" <robh@kernel.org>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"Heiko Stuebner" <heiko@sntech.de>,
	"Dragan Simic" <dsimic@manjaro.org>,
	linux-rockchip@lists.infradead.org, linux-pci@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 1/4] PCI: rockchip: drop 2.5 GT/s defines
Date: Fri, 27 Feb 2026 19:42:01 -0300	[thread overview]
Message-ID: <aaIduRsXvcUZrj8E@geday> (raw)
In-Reply-To: <878qceku1j.fsf@posteo.net>

Hi Charalampos,

On Fri, Feb 27, 2026 at 04:53:00PM +0000, Charalampos Mitrodimas wrote:
> Geraldo Nascimento <geraldogabriel@gmail.com> writes:
> 
> > Drop the 2.5 GT/s Link Speed defines from Rockchip PCIe header
> > definitions. The reason is that Shawn Lin from Rockchip has
> > reiterated that there may be danger of "catastrophic failure"
> > in using their PCIe with 5.0 GT/s speeds.
> >
> > While Rockchip has done so informally without issuing a proper
> > errata, and the particulars are thus unknown, this may cause
> > data loss or worse.
> >
> > This change is corroborated by RK3399 official datasheet [1], which
> > states maximum link speed for this platform is 2.5 GT/s.
> >
> > [1] https://opensource.rock-chips.com/images/d/d7/Rockchip_RK3399_Datasheet_V2.1-20200323.pdf
> >
> > Fixes: 956cd99b35a8 ("PCI: rockchip: Separate common code from RC driver")
> > Link: https://lore.kernel.org/all/ffd05070-9879-4468-94e3-b88968b4c21b@rock-chips.com/
> > Cc: stable@vger.kernel.org
> > Reported-by: Dragan Simic <dsimic@manjaro.org>
> > Reported-by: Shawn Lin <shawn.lin@rock-chips.com>
> > Signed-off-by: Geraldo Nascimento <geraldogabriel@gmail.com>
> > ---
> >  drivers/pci/controller/pcie-rockchip.h | 3 ---
> >  1 file changed, 3 deletions(-)
> >
> > diff --git a/drivers/pci/controller/pcie-rockchip.h b/drivers/pci/controller/pcie-rockchip.h
> > index 3e82a69b9c00..b5da15601b58 100644
> > --- a/drivers/pci/controller/pcie-rockchip.h
> > +++ b/drivers/pci/controller/pcie-rockchip.h
> > @@ -42,7 +42,6 @@
> >  #define   PCIE_CLIENT_MODE_RC			HWORD_SET_BIT(0x0040)
> >  #define   PCIE_CLIENT_MODE_EP			HWORD_CLR_BIT(0x0040)
> >  #define   PCIE_CLIENT_GEN_SEL_1			HWORD_CLR_BIT(0x0080)
> > -#define   PCIE_CLIENT_GEN_SEL_2			HWORD_SET_BIT(0x0080)
> 
> This commit alone won't compile right? PCIE_CLIENT_GEN_SEL_2 is still
> referenced by rockchip_pcie_init_port():

You are correct, thanks for catching it.

> 
>          if (rockchip->link_gen == 2)
>                  rockchip_pcie_write(rockchip, PCIE_CLIENT_GEN_SEL_2,
>                                      PCIE_CLIENT_CONFIG);
> 
> This reference is removed by the next patch in the series but not sure
> if we want to do it here instead.
> 
> >  #define PCIE_CLIENT_LEGACY_INT_CTRL	(PCIE_CLIENT_BASE + 0x0c)
> >  #define   PCIE_CLIENT_INT_IN_ASSERT		HWORD_SET_BIT(0x0002)
> >  #define   PCIE_CLIENT_INT_IN_DEASSERT		HWORD_CLR_BIT(0x0002)
> > @@ -197,8 +196,6 @@
> >  	(((x) & PCIE_CORE_PL_CONF_LS_MASK) == PCIE_CORE_PL_CONF_LS_READY)
> >  #define PCIE_LINK_UP(x) \
> >  	(((x) & PCIE_CLIENT_LINK_STATUS_MASK) == PCIE_CLIENT_LINK_STATUS_UP)
> > -#define PCIE_LINK_IS_GEN2(x) \
> > -	(((x) & PCIE_CORE_PL_CONF_SPEED_MASK) == PCIE_CORE_PL_CONF_SPEED_5G)
> 
> Same for this, references elsewhere tho.
> 

Thanks for pointing this out. I'll do better for v5.

Geraldo Nascimento

> >  
> >  #define RC_REGION_0_ADDR_TRANS_H		0x00000000
> >  #define RC_REGION_0_ADDR_TRANS_L		0x00000000