RE: [PATCH v1 3/4] can: cast: add driver for CAST CAN controller

[William Qiu]

> -----Original Message-----
> From: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
> Sent: 2024年1月29日 16:26
> To: William Qiu <william.qiu@xxxxxxxxxxxxxxxx>
> Cc: devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> linux-riscv@xxxxxxxxxxxxxxxxxxx; linux-can@xxxxxxxxxxxxxxx; Emil Renner
> Berthing <kernel@xxxxxxxx>; Rob Herring <robh+dt@xxxxxxxxxx>; Wolfgang
> Grandegger <wg@xxxxxxxxxxxxxx>; Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>;
> Krzysztof Kozlowski <krzysztof.kozlowski+dt@xxxxxxxxxx>; Conor Dooley
> <conor+dt@xxxxxxxxxx>; David S . Miller <davem@xxxxxxxxxxxxx>; Eric
> Dumazet <edumazet@xxxxxxxxxx>; Jakub Kicinski <kuba@xxxxxxxxxx>; Paolo
> Abeni <pabeni@xxxxxxxxxx>; Paul Walmsley <paul.walmsley@xxxxxxxxxx>;
> Palmer Dabbelt <palmer@xxxxxxxxxxx>; Albert Ou <aou@xxxxxxxxxxxxxxxxx>
> Subject: Re: [PATCH v1 3/4] can: cast: add driver for CAST CAN controller
> 
> Hello William Qiu,
> 
> thank you for your contribution. I've some quick notes about your driver.
> 
> On 29.01.2024 11:12:38, William Qiu wrote:
> > Add driver for CAST CAN Controller. And add compatibility code which
> > based on StarFive JH7110 SoC.
> 
> Please add yourself or someone else at starfivetech to the Maintainers file.
> 
> Please use BIT() and/or GEN_MASK() to create the _MASK enums. Please use
> FIELD_GET(), FIELD_PREP.
> 
> Please replace the ccan_ioread8() by a proper 32 bit read and use FIELD_GET to
> access any non 32 bit value. Instead of ccan_iowrite8() use FIELD_PREP and a
> proper 32 bit write.
> 
> The enum ccan_reg_bitchange looks very strange, why do you have OFF and SET
> values?
> 
> The ccan_reigister_set_bit() and ccan_reigister_off_bit() functions looks very
> strange, too. I suggest to use a 32 bit read, set, clear the bits followed by a 32 bit
> write. Having set_bit() clear_bit() functions may lead to more register accesses
> than needed, if not handled with care.
> 
> If you think the driver absolutely needs bit set/clear functions, please follow the
> name and signature of the regmap_update_bits(),
> regmap_set_bits() and regmap_clear_bits().
> 
> Please use can_put_echo_skb(), can_get_echo_skb().
> 
> Please implement proper TX-flow control. Stop the TX queue, if you HW queue is
> full, start the TX queue once the HW queue has space again.
> 
> Consider using the rx_offload helper
> 
> You claim you IRQ handler works with shared interrupts, but you return an error
> if there are no interrupts by your IP core.
> 
> Please enable the clocks during open() and disabled during close()
> 
> Marc
> 

Thank you for your notes. I will modify my driver one by one according to your notes。

Thanks,
William
> --
> Pengutronix e.K.                 | Marc Kleine-Budde          |
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