public inbox for linux-mtd@lists.infradead.org
 help / color / mirror / Atom feed
From: Herve Codina <herve.codina@bootlin.com>
To: Miquel Raynal <miquel.raynal@bootlin.com>,
	Richard Weinberger <richard@nod.at>,
	Vignesh Raghavendra <vigneshr@ti.com>
Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org,
	Herve Codina <herve.codina@bootlin.com>,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Subject: [PATCH 2/4] mtd: rawnand: fsmc: Force to use 8 bits access when expected
Date: Fri, 12 Nov 2021 15:38:53 +0100	[thread overview]
Message-ID: <20211112143855.2678989-3-herve.codina@bootlin.com> (raw)
In-Reply-To: <20211112143855.2678989-1-herve.codina@bootlin.com>

Some data transfers are expected on 8 bits by the nand core.
The fsmc driver did not check this constraint and these transfers
can be done on 32 bits depending on buffer alignment and transfers
data size.

This patch ensures that these transfers will be 8bits transfers in
all cases.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
 drivers/mtd/nand/raw/fsmc_nand.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/mtd/nand/raw/fsmc_nand.c b/drivers/mtd/nand/raw/fsmc_nand.c
index 658f0cbe7ce8..7f057cfee6c4 100644
--- a/drivers/mtd/nand/raw/fsmc_nand.c
+++ b/drivers/mtd/nand/raw/fsmc_nand.c
@@ -540,12 +540,12 @@ static int dma_xfer(struct fsmc_nand_data *host, void *buffer, int len,
  * @len:	number of bytes to write
  */
 static void fsmc_write_buf(struct fsmc_nand_data *host, const u8 *buf,
-			   int len)
+			   int len, bool force_8bit)
 {
 	int i;
 
 	if (IS_ALIGNED((uintptr_t)buf, sizeof(u32)) &&
-	    IS_ALIGNED(len, sizeof(u32))) {
+	    IS_ALIGNED(len, sizeof(u32)) && !force_8bit) {
 		u32 *p = (u32 *)buf;
 
 		len = len >> 2;
@@ -563,12 +563,13 @@ static void fsmc_write_buf(struct fsmc_nand_data *host, const u8 *buf,
  * @buf:	buffer to store date
  * @len:	number of bytes to read
  */
-static void fsmc_read_buf(struct fsmc_nand_data *host, u8 *buf, int len)
+static void fsmc_read_buf(struct fsmc_nand_data *host, u8 *buf, int len,
+			  bool force_8bit)
 {
 	int i;
 
 	if (IS_ALIGNED((uintptr_t)buf, sizeof(u32)) &&
-	    IS_ALIGNED(len, sizeof(u32))) {
+	    IS_ALIGNED(len, sizeof(u32)) && !force_8bit) {
 		u32 *p = (u32 *)buf;
 
 		len = len >> 2;
@@ -646,7 +647,8 @@ static int fsmc_exec_op(struct nand_chip *chip, const struct nand_operation *op,
 						  instr->ctx.data.len);
 			else
 				fsmc_read_buf(host, instr->ctx.data.buf.in,
-					      instr->ctx.data.len);
+					      instr->ctx.data.len,
+					      instr->ctx.data.force_8bit);
 			break;
 
 		case NAND_OP_DATA_OUT_INSTR:
@@ -656,7 +658,8 @@ static int fsmc_exec_op(struct nand_chip *chip, const struct nand_operation *op,
 						   instr->ctx.data.len);
 			else
 				fsmc_write_buf(host, instr->ctx.data.buf.out,
-					       instr->ctx.data.len);
+					       instr->ctx.data.len,
+					       instr->ctx.data.force_8bit);
 			break;
 
 		case NAND_OP_WAITRDY_INSTR:
-- 
2.31.1


______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

  parent reply	other threads:[~2021-11-12 14:53 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-12 14:38 [PATCH 0/4] mtd: rawnand: Fixes nand infra delay setting and FSMC nand controller Herve Codina
2021-11-12 14:38 ` [PATCH 1/4] mtd: rawnand: Fix nand_erase_op delay Herve Codina
2021-11-12 14:38 ` Herve Codina [this message]
2021-11-12 15:38   ` [PATCH 2/4] mtd: rawnand: fsmc: Force to use 8 bits access when expected Miquel Raynal
2021-11-17 13:47     ` Herve Codina
2021-11-12 14:38 ` [PATCH 3/4] mtd: rawnand: fsmc: Take instruction delay into account Herve Codina
2021-11-12 14:38 ` [PATCH 4/4] mtd: rawnand: fsmc: Fix timing computation Herve Codina
2021-11-12 15:52   ` Miquel Raynal

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20211112143855.2678989-3-herve.codina@bootlin.com \
    --to=herve.codina@bootlin.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mtd@lists.infradead.org \
    --cc=miquel.raynal@bootlin.com \
    --cc=richard@nod.at \
    --cc=thomas.petazzoni@bootlin.com \
    --cc=vigneshr@ti.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox