From nobody Thu Oct 2 21:58:18 2025 Received: from mail-ed1-f73.google.com (mail-ed1-f73.google.com [209.85.208.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 92158A930 for ; Wed, 10 Sep 2025 10:34:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.73 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757500499; cv=none; b=mlLFpW17UjfGdsP4CaL8CbmnLVxPUfeJ164PWe+6+hx1yay4P4Tgvk7pyU/+xFnThPkSyP4ytvY8lQQV4aUPOlS5568JUjYnfqJfmxDz/P10hAhPYm6HNHrMslE34uN0uF46YvV+w26eac8NYpVd/53XoLsEAnReaYZex1UFtRA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757500499; c=relaxed/simple; bh=zQjg8LCyE/RfH2yHJ1+N6bVu/W0mBBgSV8h8b2sqlDs=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=RXHrNOLTAY6/ZOm4JrUKvjgjRjnC2S2bBM6u9e8uhJlSkIPCzfg0vinWSeb/L0O95wh7MhzBmOLHo7PcoPNUEC7fnop9WaONCURGfl4Ch+H8/TwzemfErhWfK/UYqnCaQlxeoyRduJpuiVvf+TMyBjMP5q1BY1UUnxn7tUKWY38= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--czapiga.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=FyOECxT3; arc=none smtp.client-ip=209.85.208.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--czapiga.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="FyOECxT3" Received: by mail-ed1-f73.google.com with SMTP id 4fb4d7f45d1cf-628f17953c7so4197574a12.3 for ; Wed, 10 Sep 2025 03:34:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1757500496; x=1758105296; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=KKm0jkbqzCHbQbrD/ZyxopJILHKzxrG8LuPV9nqZYkw=; b=FyOECxT38jee8HCP9fsxq4ZNS5tE7xEK3sWtejGMsZIJ1tZWZGVDN7UyQt2T5/LXLT 4Folx62p9qVy8tFNq4kN1FAIz0T8qMZ/ZAji5KdJ0wUOIMCIjIgwyTXeKgJ4qTaKn63z hVD27S4mbRnnWDdV8HHjYG9drnYxFlMUdpMGkgkZxbtosXvHKCuEPX6Ne9Ibeg4FqBQu C8BObM+B+WMJSRV/MRSnfbpIqBoxTBk5d6QMWUucQk7MZOzLP/SuQbGpUacP3bgszgUJ PooiNUgvbRyHQYCgFhy7kCg5FtnLGaeixu1/0pqonwnCvI5bzRdb6Dv7zd+qVcDK6ty6 1jGw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1757500496; x=1758105296; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=KKm0jkbqzCHbQbrD/ZyxopJILHKzxrG8LuPV9nqZYkw=; b=DwqwpR9FyjdYzsmNQs26oahP3BacqB5tNqwU3A57NIZPQD5Tg7dcuZWNUXOxFTLgR1 AK5AQIubt4USQuYCWbIn6uwsQTLMFLXAli0FEWzwUuNtmgWimXliiG6y7xlWCqJbHb7u 9tlOdletzpklcAdUcKttsQj+cVlmXqMhVF0qIcbBfFovpnIUx9v5bM90Yj+aAaWQFlHM 2zlXgmujUd+X3KiE0TsAyj8XUoI06xXseWRp9CdkjIN4tAB4YkSSHYn86Ln6FRMQfViW 2Fz4wEAVa8P3nt8ARrmu+RPlygW4ToilcKrinQk1ofQMvzerfpjglh6Zl0CRfV32/F9m i2/w== X-Forwarded-Encrypted: i=1; AJvYcCV+mpXdVYbTX/qT+MvkigIvSfak3lyZcSufNT1Ef3W5ABjbj4WU8OK6qujlVyCQrYixI0rmilDvcm8xa0Y=@vger.kernel.org X-Gm-Message-State: AOJu0Yw9i/UbjbXIRdWuIlwGF8Pwp/MxrUdHRB2zKLOemyQ8Swyq/sF1 EiXWw1pjMn8Y6Q3fGD78R7Rg030r+dbTz+ncAi+Mf/jlLF0hR47qGELS16HsZLDPKx5v9f7PvIP f3b9vRq4jVA== X-Google-Smtp-Source: AGHT+IGQ3fHbE7naj85CdBuLACoB3D4RZfuFn7hndTTGiUVAlDir42uDdrqa3sGbCVuaMELpPzDXQbYL11XZ X-Received: from edp3.prod.google.com ([2002:a05:6402:4383:b0:61d:1dd1:5e1b]) (user=czapiga job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6402:270d:b0:62c:3878:747 with SMTP id 4fb4d7f45d1cf-62c38784cc4mr4446625a12.33.1757500495905; Wed, 10 Sep 2025 03:34:55 -0700 (PDT) Date: Wed, 10 Sep 2025 10:33:55 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.51.0.384.g4c02a37b29-goog Message-ID: <20250910103355.629421-1-czapiga@google.com> Subject: [PATCH] mtd: spi-nor: core: Check read CR support From: Jakub Czapiga To: Tudor Ambarus Cc: Pratyush Yadav , Michael Walle , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, Konrad Adamczyk , Adeel Arshad , Mika Westerberg , Jakub Czapiga Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Some SPI controllers like Intel's one on the PCI bus do not support opcode 35h. This opcode is used to read the Configuration Register on SPI-NOR chips that have 16-bit Status Register configured regardless of the controller support for it. Adding a check call in the setup step allows disabling use of the 35h opcode and falling back to the manual Status Registers management. Before: openat(AT_FDCWD, "/dev/mtd0", O_RDWR) =3D 4 ioctl(4, MIXER_WRITE(6) or MEMUNLOCK, {start=3D0, length=3D0x2000000}) =3D = -1 EOPNOTSUPP After: openat(AT_FDCWD, "/dev/mtd0", O_RDWR) =3D 4 ioctl(4, MIXER_WRITE(6) or MEMUNLOCK, {start=3D0, length=3D0x2000000}) =3D 0 ioctl(4, MIXER_WRITE(5) or MEMLOCK, {start=3D0x1800000, length=3D0x800000})= =3D 0 Suggested-by: Adeel Arshad Signed-off-by: Jakub Czapiga --- drivers/mtd/spi-nor/core.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c index ac4b960101cc..79deee3a50d3 100644 --- a/drivers/mtd/spi-nor/core.c +++ b/drivers/mtd/spi-nor/core.c @@ -2608,6 +2608,10 @@ static int spi_nor_setup(struct spi_nor *nor, } } =20 + /* Some SPI controllers might not support CR read opcode. */ + if (spi_nor_read_cr(nor, nor->bouncebuf) =3D=3D -EOPNOTSUPP) + nor->flags |=3D SNOR_F_NO_READ_CR; + /* Select the (Fast) Read command. */ err =3D spi_nor_select_read(nor, shared_mask); if (err) { --=20 2.51.0.384.g4c02a37b29-goog