From: <Tudor.Ambarus@microchip.com>
To: <danielwa@cisco.com>
Cc: <xe-linux-external@cisco.com>, <miquel.raynal@bootlin.com>,
<richard@nod.at>, <vigneshr@ti.com>,
<linux-mtd@lists.infradead.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [RFC-PATCH] mtd: spi-nor: add conditional 4B opcodes
Date: Sun, 10 May 2020 10:43:36 +0000 [thread overview]
Message-ID: <27176656.kDElnbHIDG@192.168.0.120> (raw)
In-Reply-To: <20200507162047.30788-1-danielwa@cisco.com>
Hi, Daniel,
On Thursday, May 7, 2020 7:20:47 PM EEST Daniel Walker wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the
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>
> Some chips have 4B opcodes, but there is no way to know if they have
> them. This device tree option allows platform owners to force enable 4b
> opcodes when they know their chips support it even when it can be
> automatically identified.
I would like to detect this at run-time if possible. Maybe we can distinguish
between the flavors of your flash by inspecting BFPT[16], bit 29. I'm planning
to parse the 16th dword of BFPT. What does your flash return after applying
the following patch?
diff --git a/drivers/mtd/spi-nor/sfdp.c b/drivers/mtd/spi-nor/sfdp.c
index f6038d3a3684..99f0ce57c7d0 100644
--- a/drivers/mtd/spi-nor/sfdp.c
+++ b/drivers/mtd/spi-nor/sfdp.c
@@ -457,6 +457,10 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
/* Fix endianness of the BFPT DWORDs. */
le32_to_cpu_array(bfpt.dwords, BFPT_DWORD_MAX);
+ for(i = 0; i < BFPT_DWORD_MAX; i++)
+ dev_err(nor->dev, "bfpt.dwords[%d] = %08x\n",
+ i + 1, bfpt.dwords[i]);
+
/* Number of address bytes. */
switch (bfpt.dwords[BFPT_DWORD(1)] & BFPT_DWORD1_ADDRESS_BYTES_MASK) {
case BFPT_DWORD1_ADDRESS_BYTES_3_ONLY:
@@ -972,6 +976,9 @@ static int spi_nor_parse_4bait(struct spi_nor *nor,
/* Fix endianness of the 4BAIT DWORDs. */
le32_to_cpu_array(dwords, SFDP_4BAIT_DWORD_MAX);
+ for(i = 0; i < SFDP_4BAIT_DWORD_MAX; i++)
+ dev_err(nor->dev, "4bait[%d] = %08x\n", i, dwords[i]);
+
/*
* Compute the subset of (Fast) Read commands for which the 4-byte
* version is supported.
prev parent reply other threads:[~2020-05-10 10:43 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-07 16:20 [RFC-PATCH] mtd: spi-nor: add conditional 4B opcodes Daniel Walker
2020-05-07 18:03 ` Pratyush Yadav
2020-05-07 18:13 ` Daniel Walker (danielwa)
2020-05-08 19:07 ` Pratyush Yadav
2020-05-08 19:28 ` Daniel Walker (danielwa)
2020-05-10 10:43 ` Tudor.Ambarus [this message]
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