From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ultrarisc.com (unknown [218.76.62.146]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 6308925F7A9; Mon, 11 May 2026 09:50:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=218.76.62.146 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778493039; cv=none; b=W7vuxoRikeFSP6o7Wj34yHZ1anwDSfpKhqaC5lBKEB7t7otItqGeO4A9ax/P/UPQoztcfYYRsn2HHvxQyimGTxY8cWVXZzme3+Cm7lWf75dE36WlBcWRuAjnO9iMo3Hwg9kG02W1DHy8XlEwXgzPzFcReYskj3EroTVYYqjEeek= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778493039; c=relaxed/simple; bh=Z4f8Be3tvf+DeFSTMlalpRJHUnyRF5MgEUMBJBp4awk=; h=MIME-Version:Content-Type:Subject:From:To:Cc:In-Reply-To: References:Date:Message-Id; b=nYxqC3RhCx1jxoURpwCD5pY1vbvjZQuOVal0J58scB5YXZHxZH5UAsGUzLunFEYCZlriaY5uZKInDDFleMuCZdyaEi7GeX2R0jxrt49i5VLc9T4gUdRZvA3swXS8nacLEnF5ym9fYdxMc48sKW1qwbKHczU979PWqYLOBXOzrnU= ARC-Authentication-Results:i=1; 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Mon, 11 May 2026 17:50:48 +0800 (CST) Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Subject: Re: [PATCH v7 4/4] serial: 8250_dw: Use a fixed CPR value for UltraRISC DP1000 UART From: Jia Wang To: =?utf-8?q?Ilpo_J=C3=A4rvinen?= Cc: Jia Wang , Andy Shevchenko , Greg Kroah-Hartman , Jiri Slaby , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Rob Herring , Krzysztof Kozlowski , Conor Dooley , LKML , linux-serial , linux-riscv@lists.infradead.org, devicetree@vger.kernel.org In-Reply-To: <66f322a7-70c5-13f9-3e97-6d0b18193f91@linux.intel.com> References: <20260429-ultrarisc-serial-v7-0-e475cce9e274@ultrarisc.com> <20260429-ultrarisc-serial-v7-4-e475cce9e274@ultrarisc.com> <66f322a7-70c5-13f9-3e97-6d0b18193f91@linux.intel.com> Date: Mon, 11 May 2026 17:50:05 +0800 Message-Id: <177849300569.62727.6686772792675107792.b4-reply@b4> X-Mailer: b4 0.15-dev X-Developer-Signature: v=1; a=ed25519-sha256; t=1778493005; l=2656; i=wangjia@ultrarisc.com; s=20260309; h=from:subject:message-id; bh=Z4f8Be3tvf+DeFSTMlalpRJHUnyRF5MgEUMBJBp4awk=; b=vfCokh6bFqZ+ax0cWnwoM+VdZGWYQ0/P0aQZlubUa1RX5FmYEMav3Og4jjfuFYnCCnyAf769m Xb64k1dcNjGCFNK6uczeyPiIjCLdoUqrvCldL/z2Ql8ovPdrWD0Lhef X-Developer-Key: i=wangjia@ultrarisc.com; a=ed25519; pk=XvYkrelqJIIzobY7j+nIg8rsfv5kzaOzuc1UPhd087U= X-CM-TRANSID:AQAAfwAnYUJ3pgFqlwMEAA--.3534S2 X-Coremail-Antispam: 1UD129KBjvJXoWxJF4fJrWDtF1Uur43urW3Jrb_yoW5GrWfpF 4UGFWYyF9agF13u3Z2v3WvyFZaqa129342kwsrK347tFn0kryDJFnakrWfC3Zruryjgw1a yF1j93y7Ca1UuFDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUU9l14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26r1j6r1xM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4j 6F4UM28EF7xvwVC2z280aVAFwI0_Jr0_Gr1l84ACjcxK6I8E87Iv6xkF7I0E14v26r4j6r 4UJwAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0 I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r 4UM4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628v n2kIc2xKxwCY1x0262kKe7AKxVWUtVW8ZwCY02Avz4vE-syl42xK82IYc2Ij64vIr41l4I 8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AK xVWUGVWUWwC2zVAF1VAY17CE14v26r4a6rW5MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcV AFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8I cIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r 4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjfUonmRUUUUU X-CM-SenderInfo: pzdqwylld63zxwud2x1vfou0bp/1tbiAQAEEWoBUkIAAwAEso On 2026-04-29 13:55 +0300, Ilpo Järvinen wrote: > On Wed, 29 Apr 2026, Jia Wang wrote: > > > The UltraRISC DP1000 UART does not provide the standard CPR register used > > by 8250_dw to discover port capabilities. > > > > Provide a fixed CPR value for the DP1000-specific compatible so the > > driver can configure the port correctly. > > > > Signed-off-by: Jia Wang > > Reviewed-by: Andy Shevchenko > > --- > > drivers/tty/serial/8250/8250_dw.c | 10 ++++++++++ > > 1 file changed, 10 insertions(+) > > > > diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c > > index 480f82d89856..55e40c10f46a 100644 > > --- a/drivers/tty/serial/8250/8250_dw.c > > +++ b/drivers/tty/serial/8250/8250_dw.c > > @@ -959,6 +959,15 @@ static const struct dw8250_platform_data dw8250_intc10ee = { > > .quirks = DW_UART_QUIRK_IER_KICK, > > }; > > > > +static const struct dw8250_platform_data dw8250_ultrarisc_dp1000_data = { > > + .usr_reg = DW_UART_USR, > > + .cpr_value = FIELD_PREP_CONST(DW_UART_CPR_ABP_DATA_WIDTH, 2) | > > + DW_UART_CPR_THRE_MODE | > > + DW_UART_CPR_DMA_EXTRA | > > + DW_UART_CPR_FIFO_MODE_FROM_SIZE(32), > > + .quirks = DW_UART_QUIRK_CPR_VALUE, > > Thanks for all the effort you put to this series, > > Reviewed-by: Ilpo Järvinen > > Unrelated to this patch, I suppose we wouldn't strictly need to have > DW_UART_QUIRK_CPR_VALUE in this driver as non-zero .cpr_value should be > enough to decide if the CPR quirk should be used or not (if the code is > adapted, obviously). > Thanks for the review and the tag, Ilpo. The idea of dropping the quirk flag sounds reasonable to me. I'll keep it in mind for a future cleanup patch once this series is merged. > > +}; > > + > > static const struct of_device_id dw8250_of_match[] = { > > { .compatible = "snps,dw-apb-uart", .data = &dw8250_dw_apb }, > > { .compatible = "cavium,octeon-3860-uart", .data = &dw8250_octeon_3860_data }, > > @@ -966,6 +975,7 @@ static const struct of_device_id dw8250_of_match[] = { > > { .compatible = "renesas,rzn1-uart", .data = &dw8250_renesas_rzn1_data }, > > { .compatible = "sophgo,sg2044-uart", .data = &dw8250_skip_set_rate_data }, > > { .compatible = "starfive,jh7100-uart", .data = &dw8250_skip_set_rate_data }, > > + { .compatible = "ultrarisc,dp1000-uart", .data = &dw8250_ultrarisc_dp1000_data }, > > { /* Sentinel */ } > > }; > > MODULE_DEVICE_TABLE(of, dw8250_of_match); > > > > > > -- > i. Best Regards, Jia Wang