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Date: Tue, 25 Jun 2019 11:22:24 +0530
From: Vignesh Raghavendra <vigneshr@...com>
To: Tokunori Ikegami <ikegami.t@...il.com>,
Boris Brezillon <bbrezillon@...nel.org>,
Marek Vasut <marek.vasut@...il.com>,
Richard Weinberger <richard@....at>,
Rob Herring <robh+dt@...nel.org>
CC: <devicetree@...r.kernel.org>,
Sergei Shtylyov <sergei.shtylyov@...entembedded.com>,
<linux-kernel@...r.kernel.org>, <linux-mtd@...ts.infradead.org>,
Miquel Raynal <miquel.raynal@...tlin.com>,
Mason Yang <masonccyang@...c.com.tw>,
<linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH v7 1/5] mtd: cfi_cmdset_0002: Add support for polling
status register
Hi,
On 24/06/19 10:16 PM, Tokunori Ikegami wrote:
>
[...]
>> +/*
>> + * Use status register to poll for Erase/write completion when DQ is not
>> + * supported. This is indicated by Bit[1:0] of SoftwareFeatures field in
>> + * CFI Primary Vendor-Specific Extended Query table 1.5
>> + */
>> +static int cfi_use_status_reg(struct cfi_private *cfi)
>> +{
>> + struct cfi_pri_amdstd *extp = cfi->cmdset_priv;
>> +
>> + return extp->MinorVersion >= '5' &&
>> + (extp->SoftwareFeatures & 0x3) == 0x1;
>
> Seems to be better to use defined values instead of 0x3 and 0x1 hard
> coded values.
>
Ok
>> +}
>> +
>> +static void cfi_check_err_status(struct map_info *map, unsigned long
>> adr)
>> +{
>> + struct cfi_private *cfi = map->fldrv_priv;
>> + map_word status;
>> +
>> + if (!cfi_use_status_reg(cfi))
>> + return;
>> +
>> + cfi_send_gen_cmd(0x70, cfi->addr_unlock1, 0, map, cfi,
>
> Is it not necessary to set chip->start as the base parameter for
> cfi_send_gen_cmd()?
>
Right now, I am not aware of any flash that supports status registers
and are banked (that's when chip->start can be non zero). Therefore I
did not think of using chip->start.
But anyways, I will fix this up to use chip->start here and elsewhere
for next version, assuming there will be such chips in the future.
>> + cfi->device_type, NULL);
>> + status = map_read(map, adr);
>> +
>> + if (map_word_bitsset(map, status, CMD(0x3a))) {
>> + unsigned long chipstatus = MERGESTATUS(status);
>> +
>> + if (chipstatus & CFI_SR_ESB)
>> + pr_err("%s erase operation failed, status %lx\n",
>> + map->name, chipstatus);
>> + if (chipstatus & CFI_SR_PSB)
>> + pr_err("%s program operation failed, status %lx\n",
>> + map->name, chipstatus);
>> + if (chipstatus & CFI_SR_WBASB)
>> + pr_err("%s buffer program command aborted, status %lx\n",
>> + map->name, chipstatus);
>> + if (chipstatus & CFI_SR_SLSB)
>> + pr_err("%s sector write protected, status %lx\n",
>> + map->name, chipstatus);
>> + }
>> +}
>> /* #define DEBUG_CFI_FEATURES */
>> @@ -744,8 +796,22 @@ static struct mtd_info *cfi_amdstd_setup(struct
>> mtd_info *mtd)
>> */
>> static int __xipram chip_ready(struct map_info *map, unsigned long
>> addr)
>> {
>> + struct cfi_private *cfi = map->fldrv_priv;
>> map_word d, t;
>> + if (cfi_use_status_reg(cfi)) {
>> + map_word ready = CMD(CFI_SR_DRB);
>> + /*
>> + * For chips that support status register, check device
>> + * ready bit
>> + */
>> + cfi_send_gen_cmd(0x70, cfi->addr_unlock1, 0, map, cfi,
>
> Same comment as cfi_check_err_status() about the base address.
>
>> + cfi->device_type, NULL);
>> + d = map_read(map, addr);
>> +
>> + return map_word_andequal(map, d, ready, ready);
>> + }
>> +
>> d = map_read(map, addr);
>> t = map_read(map, addr);
>> @@ -769,8 +835,27 @@ static int __xipram chip_ready(struct map_info
>> *map, unsigned long addr)
>> */
>> static int __xipram chip_good(struct map_info *map, unsigned long
>> addr, map_word expected)
>> {
>> + struct cfi_private *cfi = map->fldrv_priv;
>> map_word oldd, curd;
>> + if (cfi_use_status_reg(cfi)) {
>> + map_word ready = CMD(CFI_SR_DRB);
>> + map_word err = CMD(CFI_SR_PSB | CFI_SR_ESB);
>
> Is it not necessary to check CFI_SR_WBASB and CFI_SR_SLSB that are
> checked by cfi_check_err_status()?
>
chip_good() is used to verify whether write or erase operation really
succeeded. Looking at Cypress HyperFlash datasheets and app notes on
status register polling, its enough to see if CFI_SR_PSB or CFI_SR_PSB
is set to know if write or erase failed. Now, the reason for program or
erase failure can be known by looking at CFI_SR_WBASB and CFI_SR_SLSB
which is done for cfi_check_err_status().
Therefore, I feel, its enough to look for CFI_SR_PSB or CFI_SR_ESB here.
Thanks for the review!
Regards
Vignesh
>> + /*
>> + * For chips that support status register, check device
>> + * ready bit and Erase/Program status bit to know if
>> + * operation succeeded.
>> + */
>> + cfi_send_gen_cmd(0x70, cfi->addr_unlock1, 0, map, cfi,
>
> Same as cfi_check_err_status() and chip_ready() about the base address.
>
>> + cfi->device_type, NULL);
>> + curd = map_read(map, addr);
>> +
>> + if (map_word_andequal(map, curd, ready, ready))
>> + return !map_word_bitsset(map, curd, err);
>> +
>> + return 0;
>> + }
>> +
>> oldd = map_read(map, addr);
>> curd = map_read(map, addr);
>> @@ -1644,6 +1729,7 @@ static int __xipram do_write_oneword(struct
>> map_info *map, struct flchip *chip,
>> /* Did we succeed? */
>> if (!chip_good(map, adr, datum)) {
>> /* reset on all failures. */
>> + cfi_check_err_status(map, adr);
>> map_write(map, CMD(0xF0), chip->start);
>> /* FIXME - should have reset delay before continuing */
>> @@ -1901,6 +1987,7 @@ static int __xipram do_write_buffer(struct
>> map_info *map, struct flchip *chip,
>> * See e.g.
>> *
>> http://www.spansion.com/Support/Application%20Notes/MirrorBit_Write_Buffer_Prog_Page_Buffer_Read_AN.pdf
>>
>> */
>> + cfi_check_err_status(map, adr);
>> cfi_send_gen_cmd(0xAA, cfi->addr_unlock1, chip->start, map, cfi,
>> cfi->device_type, NULL);
>> cfi_send_gen_cmd(0x55, cfi->addr_unlock2, chip->start, map, cfi,
>> @@ -2107,6 +2194,7 @@ static int do_panic_write_oneword(struct
>> map_info *map, struct flchip *chip,
>> if (!chip_good(map, adr, datum)) {
>> /* reset on all failures. */
>> + cfi_check_err_status(map, adr);
>> map_write(map, CMD(0xF0), chip->start);
>> /* FIXME - should have reset delay before continuing */
>> @@ -2316,6 +2404,7 @@ static int __xipram do_erase_chip(struct
>> map_info *map, struct flchip *chip)
>> /* Did we succeed? */
>> if (ret) {
>> /* reset on all failures. */
>> + cfi_check_err_status(map, adr);
>> map_write(map, CMD(0xF0), chip->start);
>> /* FIXME - should have reset delay before continuing */
>> @@ -2412,6 +2501,7 @@ static int __xipram do_erase_oneblock(struct
>> map_info *map, struct flchip *chip,
>> /* Did we succeed? */
>> if (ret) {
>> /* reset on all failures. */
>> + cfi_check_err_status(map, adr);
>> map_write(map, CMD(0xF0), chip->start);
>> /* FIXME - should have reset delay before continuing */
>> diff --git a/include/linux/mtd/cfi.h b/include/linux/mtd/cfi.h
>> index 208c87cf2e3e..b50416169049 100644
>> --- a/include/linux/mtd/cfi.h
>> +++ b/include/linux/mtd/cfi.h
>> @@ -219,6 +219,11 @@ struct cfi_pri_amdstd {
>> uint8_t VppMin;
>> uint8_t VppMax;
>> uint8_t TopBottom;
>> + /* Below field are added from version 1.5 */
>> + uint8_t ProgramSuspend;
>> + uint8_t UnlockBypass;
>> + uint8_t SecureSiliconSector;
>> + uint8_t SoftwareFeatures;
>> } __packed;
>> /* Vendor-Specific PRI for Atmel chips (command set 0x0002) */
--
Regards
Vignesh
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